Bertrand Poumellec - Academia.edu (original) (raw)

Papers by Bertrand Poumellec

Research paper thumbnail of On the Formation of Nanogratings in Commercial Oxide Glasses by Femtosecond Laser Direct Writing

Nanomaterials, Aug 29, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Formation of nanogratings driven by ultrafast laser irradiation in mid-IR heavy oxide glasses

Ceramics International, Nov 1, 2022

This work demonstrates for the first time the formation of nanogratings inside Barium Gallo-Germa... more This work demonstrates for the first time the formation of nanogratings inside Barium Gallo-Germanate glasses using femtosecond laser direct writing. These heavy oxide glasses, with a characterized transparency window up to 6 µm, along with the polarization sensitive birefringent nanostructures induced by femtosecond laser, offer an excellent platform for the development of mid-Infrared photonic applications. The fabricated glasses, containing both rare earth (Gd, Y) and transition metals (Zn, Ta), are directly compared to amorphous GeO2 and commercial aluminogermanate (Corning-9754) glasses commonly used in this field. The nanogratings processing window in each glass was investigated by varying laser parameters (pulse duration, energy, repetition rate), and electron microscopy imaging directly evidenced the porous nanostructures. Among the results, a strong form birefringence in 8% ZnO-BGG glass, e.g., up to-0.029±0.001 was reported. Finally, birefringent embedded Fresnel GRIN plates were directly written in a BGG glass, to demonstrate the functionalization potential of these materials.

Research paper thumbnail of Femtosecond Laser-Induced Crystallization in Glasses: Growth Dynamics for Orientable Nanostructure and Nanocrystallization

Crystal Growth & Design, Feb 28, 2019

Research paper thumbnail of Stress-induced optical waveguides written by an ultrafast laser in Nd3+, Y3+ co-doped SrF2 crystals

Applied Optics, Jan 28, 2019

High refractive index contrast, birefringence and luminescence properties of written channel wave... more High refractive index contrast, birefringence and luminescence properties of written channel waveguides inside fluoride crystals written by femtosecond (fs) laser have been studied. Herein, fs laser-induced stress affected zone is an efficient tool to create birefringence and high refractive index contrast in Nd 3+ , Y 3+ codoped SrF 2 crystal for wide range of pulse energies and repetition rates. In fabricating the waveguides at high repetition rate (typ. 500 kHz), we avoided too much heat accumulation, and thus they exhibit lower propagation loss in codoped SrF 2 crystal (1.63 ± 0.21 dB/cm for TM-polarization). The measured retardance can be interpreted as related to stress-induced birefringence in response to free of stress volume expansion photoinduced in the non-spherical irradiated zone. The photoluminescence and lifetime measurements are also carried out in order to understand local changes of the network in and around femtosecond laser induced waveguides written in codoped SrF 2 crystal.

Research paper thumbnail of 3D structured Bessel beam polarization and its application to imprint chiral optical properties in silica

arXiv (Cornell University), Mar 17, 2023

Polarization plays crucial role in light-matter interactions; hence its overall manipulation is a... more Polarization plays crucial role in light-matter interactions; hence its overall manipulation is an essential key to unlock the versatility of light manufacturing, especially in femtosecond laser direct writing. Existing polarization-shaping techniques, however, only focus on the manipulation in transverse plane of a light beam, namely a two-dimensional control. In this paper, we propose a novel passive strategy that exploits a class of femtosecond laser written space varying birefringent elements, to shape the polarization state along the optical path. As a demonstration, we generate a three-dimensional structured Bessel beam whose linear polarization state is slowly evolving along the focus (typ. 90° within 60). Such a "helical polarized" Bessel beam allows imprinting "twisted nanogratings" in SiO2 resulting in an extrinsic optical chirality at a micrometric scale, which owns a high optical rotation. Our work brings new perspectives for threedimensional polarization manipulations and would find applications in structured light, light-matter interaction and chiral device fabrication.

Research paper thumbnail of Tailoring chiral optical properties by femtosecond laser direct writing in silica

Light: Science & Applications

An object that possesses chirality, that is, having its mirror image not overlayed on itself by r... more An object that possesses chirality, that is, having its mirror image not overlayed on itself by rotation and translation, can provide a different optical response to a left- or right-handed circular polarized light. Chiral nanostructures may exhibit polarization-selective optical properties that can be controlled for micro-to-nano optical element engineering. An attractive way to induce such complex nanostructures in three-dimension in glass is femtosecond laser direct writing. However, the mechanism of femtosecond laser induced chirality remains to be unveiled due to complex physical and chemical processes occurring during the ultrashort light-matter interaction. Here, a phenomenological model is proposed and is built on two-layers phase shifters to account for this laser-induced optical chirality in an initially achiral material (silica glass). This model is based on the observation that femtosecond laser induced nanogratings own two principal contributions to its aggregate birefr...

Research paper thumbnail of Photosensitivity of Infrared Glasses under Femtosecond Laser Direct Writing for mid-IR Applications

Applied sciences, Sep 1, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Three Dimensional Writing of Material Functions by femtosecond laser: Science and Technology

HAL (Le Centre pour la Communication Scientifique Directe), Jun 21, 2020

Research paper thumbnail of Direct writing of low-loss birefringent laser waveguides in Nd 3+ , Y 3+ codoped SrF 2 crystal by ultrafast laser

Applied Optics, 2019

High refractive index contrast, birefringence and luminescence properties of written channel wave... more High refractive index contrast, birefringence and luminescence properties of written channel waveguides inside fluoride crystals written by femtosecond (fs) laser have been studied. Herein, fs laser-induced stress affected zone is an efficient tool to create birefringence and high refractive index contrast in Nd 3+ , Y 3+ codoped SrF 2 crystal for wide range of pulse energies and repetition rates. In fabricating the waveguides at high repetition rate (typ. 500 kHz), we avoided too much heat accumulation, and thus they exhibit lower propagation loss in codoped SrF 2 crystal (1.63 ± 0.21 dB/cm for TM-polarization). The measured retardance can be interpreted as related to stress-induced birefringence in response to free of stress volume expansion photo-induced in the non-spherical irradiated zone. The photoluminescence and lifetime measurements are also carried out in order to understand local changes of the network in and around femtosecond laser induced waveguides written in codoped ...

Research paper thumbnail of A Comparison between Nanogratings-Based and Stress-Engineered Waveplates Written by Femtosecond Laser in Silica

Micromachines, 2020

This paper compares anisotropic linear optical properties (linear birefringence, linear dichroism... more This paper compares anisotropic linear optical properties (linear birefringence, linear dichroism, degree of polarization) and performances (absorption coefficient, thermal stability) of two types of birefringent waveplates fabricated in silica glass by femtosecond laser direct writing. The first type of waveplate is based on birefringence induced by self-organized nanogratings imprinted in the glass. One the other hand, the second design is based on birefringence originating from the stress-field formed around the aforementioned nanogratings. In addition to the provided comparison, the manufacturing of stress-engineered half waveplates in the UV-Visible range, and with mm-size clear aperture and negligible excess losses, is reported. Such results contrast with waveplates made of nanogratings, as the later exhibit significantly higher scattering losses and depolarization effects in the UV-Visible range.

Research paper thumbnail of Low Loss Multimode Optical Fibers via Fictive Temperature Reduction by Means of Outer-Cladding Na Doping

Journal of Lightwave Technology, 2016

The reduction of the intrinsic Rayleigh scattering of the optical fibers by slightly altering the... more The reduction of the intrinsic Rayleigh scattering of the optical fibers by slightly altering the outer-cladding composition via the introduction of alkali is the goal of this paper. In this view, multimode fibers with Al-and Na-doped outer-cladding were fabricated via the PCVD process. In optimal conditions (typ. 10-80 ppm Na), we obtained a reduction of 0.06 dB/km at 850 nm for 50/125 multimode fibers corresponding to an attenuation decrease from 2.21 dB/km down to 2.15 dB/km. This is attributed to Rayleigh scattering reduction due to a fictive temperature lowering. In addition, the minor amounts of Na incorporated in the outer-cladding results in much lower NBOHC defects related absorption at 650 nm.

Research paper thumbnail of Dependence of the femtosecond laser damage thresholds with the chemical composition of the glass

Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, 2003

ABSTRACT

Research paper thumbnail of UV Excited Luminescence Behavior in OH-Flooded Ge-Doped Silica Preform Plates Exposed to 193nm Laser Light

Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, 2007

ABSTRACT We studied the influence of OH-flooding treatment and subsequent UV exposure on the phot... more ABSTRACT We studied the influence of OH-flooding treatment and subsequent UV exposure on the photo-luminescence excitation spectra. We compare the 193nm laser induced absorption and photo-luminescence excitation changes in Ge-doped silica glass.

Research paper thumbnail of Profile Amplitude Measurement and Phase Shifts Localization in Fiber Bragg Gratings Using UV-Induced Blue Luminescence

Conference on Lasers and Electro-Optics 2012, 2012

ABSTRACT We report a highly sensitive UV-induced blue luminescence technique for profile amplitud... more ABSTRACT We report a highly sensitive UV-induced blue luminescence technique for profile amplitude and phase measurement in long fiber Bragg gratings. An index modulation as weak as 10-5 and a spatial resolution of ~100μm have been obtained.

Research paper thumbnail of Reliable lifetime prediction of gain flattening filters

Advanced Photonics, 2014

This paper is dedicated to the lifetime prediction of Gain Flattening Filters. Based on the maste... more This paper is dedicated to the lifetime prediction of Gain Flattening Filters. Based on the master curve formalism, we predicted the ageing of the refractive index profile. Finally we modeled the spectral response of GFF under ageing.

Research paper thumbnail of Doping Dependence of the Femtosecond Laser Damage Thresholds in Silica Glasses

Frontiers in Optics 2009/Laser Science XXV/Fall 2009 OSA Optics & Photonics Technical Digest, 2009

We observed that the first threshold (i.e. permanent isotropic index change) is not significantly... more We observed that the first threshold (i.e. permanent isotropic index change) is not significantly dependent on the doping whereas it is the contrary for the second threshold (i.e. permanent linear birefringence).

Research paper thumbnail of Fictive temperature in silica-based glasses and its application to optical fiber manufacturing

Progress in Materials Science, 2012

This paper will thus give an overview of methods to reduce efficiently the Rayleigh scattering lo... more This paper will thus give an overview of methods to reduce efficiently the Rayleigh scattering loss via the fictive temperature in silica-based optical fibers. We will first recall what the concept of fictive temperature T f is and its limitations in section 2. We will see that both Raman and IR spectroscopy can be used to determine T f (Section 3). Section 4 will thus give some examples of T f profiles measured in optical fibers manufactured in different conditions. Finally, section 5 will present the main approaches to reduce Rayleigh scattering loss in silica-based fibers via a reduction of T f .

Research paper thumbnail of Femtosecond laser irradiation stress induced in pure silica

Optics Express, 2003

We reveal stress fields induced by femtosecond laser irradiation by investigating the topography ... more We reveal stress fields induced by femtosecond laser irradiation by investigating the topography of surface relaxation of a cleavage of silica plates in which irradiation was performed, varying intensity, laser polarization and displacement of the writing beam. The stress field appears to depend on the writing parameters differently according to the laser intensity. For pulse intensity larger than 0.1 µJ, a first shear stress developed. Above 0.25 µJ, another shear stress appears that is dependent on the direction of writing and coupling with a phase matching condition between the pump wave and the third harmonic.

Research paper thumbnail of Femtosecond laser direct writing in SiO <sub>2</sub> ‐Al <sub>2</sub> O <sub>3</sub> binary glasses and thermal stability of <i>Type II</i> permanent modifications

Journal of the American Ceramic Society, May 7, 2020

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Research paper thumbnail of Thermodynamic properties of titanium dioxide, niobium dioxide and their solid solutions at high temperature

Journal of Physics and Chemistry of Solids, 1985

By means of thermogravimetric measurements, it has been possible to obtain information on the nat... more By means of thermogravimetric measurements, it has been possible to obtain information on the nature of the intrinsic and extrinsic defects of TiO 2 , NbO 2 and solid solutions Nb y Ti 1−y O 2±x Pure TiO 2 is an oxygen-deficient oxide The main defects are oxygen ...

Research paper thumbnail of On the Formation of Nanogratings in Commercial Oxide Glasses by Femtosecond Laser Direct Writing

Nanomaterials, Aug 29, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Formation of nanogratings driven by ultrafast laser irradiation in mid-IR heavy oxide glasses

Ceramics International, Nov 1, 2022

This work demonstrates for the first time the formation of nanogratings inside Barium Gallo-Germa... more This work demonstrates for the first time the formation of nanogratings inside Barium Gallo-Germanate glasses using femtosecond laser direct writing. These heavy oxide glasses, with a characterized transparency window up to 6 µm, along with the polarization sensitive birefringent nanostructures induced by femtosecond laser, offer an excellent platform for the development of mid-Infrared photonic applications. The fabricated glasses, containing both rare earth (Gd, Y) and transition metals (Zn, Ta), are directly compared to amorphous GeO2 and commercial aluminogermanate (Corning-9754) glasses commonly used in this field. The nanogratings processing window in each glass was investigated by varying laser parameters (pulse duration, energy, repetition rate), and electron microscopy imaging directly evidenced the porous nanostructures. Among the results, a strong form birefringence in 8% ZnO-BGG glass, e.g., up to-0.029±0.001 was reported. Finally, birefringent embedded Fresnel GRIN plates were directly written in a BGG glass, to demonstrate the functionalization potential of these materials.

Research paper thumbnail of Femtosecond Laser-Induced Crystallization in Glasses: Growth Dynamics for Orientable Nanostructure and Nanocrystallization

Crystal Growth & Design, Feb 28, 2019

Research paper thumbnail of Stress-induced optical waveguides written by an ultrafast laser in Nd3+, Y3+ co-doped SrF2 crystals

Applied Optics, Jan 28, 2019

High refractive index contrast, birefringence and luminescence properties of written channel wave... more High refractive index contrast, birefringence and luminescence properties of written channel waveguides inside fluoride crystals written by femtosecond (fs) laser have been studied. Herein, fs laser-induced stress affected zone is an efficient tool to create birefringence and high refractive index contrast in Nd 3+ , Y 3+ codoped SrF 2 crystal for wide range of pulse energies and repetition rates. In fabricating the waveguides at high repetition rate (typ. 500 kHz), we avoided too much heat accumulation, and thus they exhibit lower propagation loss in codoped SrF 2 crystal (1.63 ± 0.21 dB/cm for TM-polarization). The measured retardance can be interpreted as related to stress-induced birefringence in response to free of stress volume expansion photoinduced in the non-spherical irradiated zone. The photoluminescence and lifetime measurements are also carried out in order to understand local changes of the network in and around femtosecond laser induced waveguides written in codoped SrF 2 crystal.

Research paper thumbnail of 3D structured Bessel beam polarization and its application to imprint chiral optical properties in silica

arXiv (Cornell University), Mar 17, 2023

Polarization plays crucial role in light-matter interactions; hence its overall manipulation is a... more Polarization plays crucial role in light-matter interactions; hence its overall manipulation is an essential key to unlock the versatility of light manufacturing, especially in femtosecond laser direct writing. Existing polarization-shaping techniques, however, only focus on the manipulation in transverse plane of a light beam, namely a two-dimensional control. In this paper, we propose a novel passive strategy that exploits a class of femtosecond laser written space varying birefringent elements, to shape the polarization state along the optical path. As a demonstration, we generate a three-dimensional structured Bessel beam whose linear polarization state is slowly evolving along the focus (typ. 90° within 60). Such a "helical polarized" Bessel beam allows imprinting "twisted nanogratings" in SiO2 resulting in an extrinsic optical chirality at a micrometric scale, which owns a high optical rotation. Our work brings new perspectives for threedimensional polarization manipulations and would find applications in structured light, light-matter interaction and chiral device fabrication.

Research paper thumbnail of Tailoring chiral optical properties by femtosecond laser direct writing in silica

Light: Science & Applications

An object that possesses chirality, that is, having its mirror image not overlayed on itself by r... more An object that possesses chirality, that is, having its mirror image not overlayed on itself by rotation and translation, can provide a different optical response to a left- or right-handed circular polarized light. Chiral nanostructures may exhibit polarization-selective optical properties that can be controlled for micro-to-nano optical element engineering. An attractive way to induce such complex nanostructures in three-dimension in glass is femtosecond laser direct writing. However, the mechanism of femtosecond laser induced chirality remains to be unveiled due to complex physical and chemical processes occurring during the ultrashort light-matter interaction. Here, a phenomenological model is proposed and is built on two-layers phase shifters to account for this laser-induced optical chirality in an initially achiral material (silica glass). This model is based on the observation that femtosecond laser induced nanogratings own two principal contributions to its aggregate birefr...

Research paper thumbnail of Photosensitivity of Infrared Glasses under Femtosecond Laser Direct Writing for mid-IR Applications

Applied sciences, Sep 1, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Three Dimensional Writing of Material Functions by femtosecond laser: Science and Technology

HAL (Le Centre pour la Communication Scientifique Directe), Jun 21, 2020

Research paper thumbnail of Direct writing of low-loss birefringent laser waveguides in Nd 3+ , Y 3+ codoped SrF 2 crystal by ultrafast laser

Applied Optics, 2019

High refractive index contrast, birefringence and luminescence properties of written channel wave... more High refractive index contrast, birefringence and luminescence properties of written channel waveguides inside fluoride crystals written by femtosecond (fs) laser have been studied. Herein, fs laser-induced stress affected zone is an efficient tool to create birefringence and high refractive index contrast in Nd 3+ , Y 3+ codoped SrF 2 crystal for wide range of pulse energies and repetition rates. In fabricating the waveguides at high repetition rate (typ. 500 kHz), we avoided too much heat accumulation, and thus they exhibit lower propagation loss in codoped SrF 2 crystal (1.63 ± 0.21 dB/cm for TM-polarization). The measured retardance can be interpreted as related to stress-induced birefringence in response to free of stress volume expansion photo-induced in the non-spherical irradiated zone. The photoluminescence and lifetime measurements are also carried out in order to understand local changes of the network in and around femtosecond laser induced waveguides written in codoped ...

Research paper thumbnail of A Comparison between Nanogratings-Based and Stress-Engineered Waveplates Written by Femtosecond Laser in Silica

Micromachines, 2020

This paper compares anisotropic linear optical properties (linear birefringence, linear dichroism... more This paper compares anisotropic linear optical properties (linear birefringence, linear dichroism, degree of polarization) and performances (absorption coefficient, thermal stability) of two types of birefringent waveplates fabricated in silica glass by femtosecond laser direct writing. The first type of waveplate is based on birefringence induced by self-organized nanogratings imprinted in the glass. One the other hand, the second design is based on birefringence originating from the stress-field formed around the aforementioned nanogratings. In addition to the provided comparison, the manufacturing of stress-engineered half waveplates in the UV-Visible range, and with mm-size clear aperture and negligible excess losses, is reported. Such results contrast with waveplates made of nanogratings, as the later exhibit significantly higher scattering losses and depolarization effects in the UV-Visible range.

Research paper thumbnail of Low Loss Multimode Optical Fibers via Fictive Temperature Reduction by Means of Outer-Cladding Na Doping

Journal of Lightwave Technology, 2016

The reduction of the intrinsic Rayleigh scattering of the optical fibers by slightly altering the... more The reduction of the intrinsic Rayleigh scattering of the optical fibers by slightly altering the outer-cladding composition via the introduction of alkali is the goal of this paper. In this view, multimode fibers with Al-and Na-doped outer-cladding were fabricated via the PCVD process. In optimal conditions (typ. 10-80 ppm Na), we obtained a reduction of 0.06 dB/km at 850 nm for 50/125 multimode fibers corresponding to an attenuation decrease from 2.21 dB/km down to 2.15 dB/km. This is attributed to Rayleigh scattering reduction due to a fictive temperature lowering. In addition, the minor amounts of Na incorporated in the outer-cladding results in much lower NBOHC defects related absorption at 650 nm.

Research paper thumbnail of Dependence of the femtosecond laser damage thresholds with the chemical composition of the glass

Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, 2003

ABSTRACT

Research paper thumbnail of UV Excited Luminescence Behavior in OH-Flooded Ge-Doped Silica Preform Plates Exposed to 193nm Laser Light

Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, 2007

ABSTRACT We studied the influence of OH-flooding treatment and subsequent UV exposure on the phot... more ABSTRACT We studied the influence of OH-flooding treatment and subsequent UV exposure on the photo-luminescence excitation spectra. We compare the 193nm laser induced absorption and photo-luminescence excitation changes in Ge-doped silica glass.

Research paper thumbnail of Profile Amplitude Measurement and Phase Shifts Localization in Fiber Bragg Gratings Using UV-Induced Blue Luminescence

Conference on Lasers and Electro-Optics 2012, 2012

ABSTRACT We report a highly sensitive UV-induced blue luminescence technique for profile amplitud... more ABSTRACT We report a highly sensitive UV-induced blue luminescence technique for profile amplitude and phase measurement in long fiber Bragg gratings. An index modulation as weak as 10-5 and a spatial resolution of ~100μm have been obtained.

Research paper thumbnail of Reliable lifetime prediction of gain flattening filters

Advanced Photonics, 2014

This paper is dedicated to the lifetime prediction of Gain Flattening Filters. Based on the maste... more This paper is dedicated to the lifetime prediction of Gain Flattening Filters. Based on the master curve formalism, we predicted the ageing of the refractive index profile. Finally we modeled the spectral response of GFF under ageing.

Research paper thumbnail of Doping Dependence of the Femtosecond Laser Damage Thresholds in Silica Glasses

Frontiers in Optics 2009/Laser Science XXV/Fall 2009 OSA Optics & Photonics Technical Digest, 2009

We observed that the first threshold (i.e. permanent isotropic index change) is not significantly... more We observed that the first threshold (i.e. permanent isotropic index change) is not significantly dependent on the doping whereas it is the contrary for the second threshold (i.e. permanent linear birefringence).

Research paper thumbnail of Fictive temperature in silica-based glasses and its application to optical fiber manufacturing

Progress in Materials Science, 2012

This paper will thus give an overview of methods to reduce efficiently the Rayleigh scattering lo... more This paper will thus give an overview of methods to reduce efficiently the Rayleigh scattering loss via the fictive temperature in silica-based optical fibers. We will first recall what the concept of fictive temperature T f is and its limitations in section 2. We will see that both Raman and IR spectroscopy can be used to determine T f (Section 3). Section 4 will thus give some examples of T f profiles measured in optical fibers manufactured in different conditions. Finally, section 5 will present the main approaches to reduce Rayleigh scattering loss in silica-based fibers via a reduction of T f .

Research paper thumbnail of Femtosecond laser irradiation stress induced in pure silica

Optics Express, 2003

We reveal stress fields induced by femtosecond laser irradiation by investigating the topography ... more We reveal stress fields induced by femtosecond laser irradiation by investigating the topography of surface relaxation of a cleavage of silica plates in which irradiation was performed, varying intensity, laser polarization and displacement of the writing beam. The stress field appears to depend on the writing parameters differently according to the laser intensity. For pulse intensity larger than 0.1 µJ, a first shear stress developed. Above 0.25 µJ, another shear stress appears that is dependent on the direction of writing and coupling with a phase matching condition between the pump wave and the third harmonic.

Research paper thumbnail of Femtosecond laser direct writing in SiO <sub>2</sub> ‐Al <sub>2</sub> O <sub>3</sub> binary glasses and thermal stability of <i>Type II</i> permanent modifications

Journal of the American Ceramic Society, May 7, 2020

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Research paper thumbnail of Thermodynamic properties of titanium dioxide, niobium dioxide and their solid solutions at high temperature

Journal of Physics and Chemistry of Solids, 1985

By means of thermogravimetric measurements, it has been possible to obtain information on the nat... more By means of thermogravimetric measurements, it has been possible to obtain information on the nature of the intrinsic and extrinsic defects of TiO 2 , NbO 2 and solid solutions Nb y Ti 1−y O 2±x Pure TiO 2 is an oxygen-deficient oxide The main defects are oxygen ...