Nicolas Tiercelin | Centre National de la Recherche Scientifique / French National Centre for Scientific Research (original) (raw)

Papers by Nicolas Tiercelin

John Wiley & Sons, Ltd eBooks, Feb 5, 2016

As the need for energy efficient data processing and data storage booms, numerous efforts are mad... more As the need for energy efficient data processing and data storage booms, numerous efforts are made by research laboratories and industrials to develop the next generation of random access memories. In a 2013 report on emerging technologies to prepare for the post-CMOS era, the International Technology Roadmap for Semiconductors underlines the necessity to "Identify the most promising technical approach(es) to obtain electrically accessible, high-speed, highdensity, low-power, (preferably) embeddable volatile and nonvolatile memories" [1]. In 2009, Mark Kryder and Chang Soo Kim compared the different existing approaches and technologies for the next generation [2]. They described the following solutions: ferroelectric random access memory (FRAM), magnetic memory (MRAM), spin torque transfer magnetic memory (STTRAM), phase change memory (PCRAM), carbon nanotube memory (NRAM), probe memories, holographic memory, conductive bridge memory (CBRAM), resistive memory (RRAM), racetrack memory, one electron memory (SEM), molecular memory and polymer memory. Among all these, the authors argued that only RRAM, CBRAM STTRAM and PCRAM seemed to be viable in the long run. The 2013 ITRS report confirmed this analysis and added carbon-based devices as well as Mott memories to the list of emerging technologies. Both studies are omitting the use of multiferroic materials, possessing coupled ferroelectric Nanomagnetic and Spintronic Devices for Energy-Efficient Memory and Computing, First Edition. Edited by Jayasimha Atulasimha and Supriyo Bandyopadhyay.

Fizika tverdogo tela, 2020

Исследованы магнитные свойства и ферромагнитный резонанс в гетероструктуре, состоящей из эпитакси... more Исследованы магнитные свойства и ферромагнитный резонанс в гетероструктуре, состоящей из эпитаксиальной пленки железо-иттриевого граната (Y 3 Fe5O 12) и редкоземельной интерметаллической сверхрешетки нанометровой толщины, представляющая собой обменно-связанные слои (TbCo 2 /FeCo)n. Сверхрешетка (TbCo 2 /FeCo)n обеспечивает гигантскую магнитострикцию и управляемую наведенную магнитную анизотропию, индуцированную магнитным полем или упругими напряжениями. Было экспериментально обнаружено магнитное взаимодействие пленок в гетероструктуре (TbCo 2 /FeCo)n/Y 3 Fe5O 12 и зарегистрирован спиновый ток, протекающий через их границу.

HAL (Le Centre pour la Communication Scientifique Directe), 2009

Journal of Magnetism and Magnetic Materials, Aug 1, 2018

Stress-mediated magnetoelectric heterostructures represent a very promising approach for the real... more Stress-mediated magnetoelectric heterostructures represent a very promising approach for the realization of ultra-low energy Random Access Memories. The magnetoelectric writing of information has been extensively studied in the past, but it was demontrated only recently that the magnetoelectric effect can also provide means for reading the stored information. We hereby theoretically study the dynamic behaviour of a magnetoelectric random access memory cell (MELRAM) typically composed of a magnetostrictive multilayer N × (TbCo 2 /FeCo) that is elastically coupled with a <011> PMN-PT ferroelectric crystal and placed in a Wheatstone bridge-like configuration. The numerical resolution of the LLG and electrodynamics equation system demonstrates high speed write and read operations with an associated extra-low energy consumption. In this model, the reading energy for a 50nm cell size is estimated to be less than 5 aJ/bit.

Physical review applied, Apr 13, 2022

Electrical control of conjugate degrees of freedom in multiferroics provides the advantage of red... more Electrical control of conjugate degrees of freedom in multiferroics provides the advantage of reducing energy consumption to femto-and even attojoules per switch in spintronics and memory devices. This is achieved through the development of technologies that make it possible to fabricate artificial materials with constantly improving properties. Here, we present the design, physics, and characteristics of a composite multiferroic spintronic emitter, which provides electrical control of the emitted terahertz (THz) wave polarization. The effect is due to electrical control of the magnetization in a high-quality magnetostrictive superlattice, TbCo2/FeCo, deposited on an anisotropic piezoelectric substrate. In our approach, several mechanisms are realized in the system simultaneously: the strain-mediated coupling of the magnetic and piezoelectric subsystems, which operate in the range of the spin-reorientation transition of the magnetic superlattice, and THz-wave generation in the superlattice by an optical femtosecond pulse. This provides flexibility and control of the set of parameters. We determine the magnetoelectric parameter, which is responsible for THz polarization control. Our results offer a significant fundamental insight into the physics of composite multiferroic systems that can be used for applications of multiferroicity, primarily for THz spintronic emitters. We believe that our findings represent a decisive step towards technologies for other types of spintronic and memory devices.

Ferroelectrics, Aug 18, 2018

HAL (Le Centre pour la Communication Scientifique Directe), May 12, 2011

International audienc

HAL (Le Centre pour la Communication Scientifique Directe), Mar 20, 2018

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.

HAL (Le Centre pour la Communication Scientifique Directe), Dec 23, 2011

HAL (Le Centre pour la Communication Scientifique Directe), 2013

HAL (Le Centre pour la Communication Scientifique Directe), Aug 28, 2017

domain wall motion induced by mechanical stress. In our simulations based on an ad-hoc procedure,... more domain wall motion induced by mechanical stress. In our simulations based on an ad-hoc procedure, a magnetoelastic nanostripe comprising two domains is coupled to a <011> cut PMN-PT piezoelectric substrate. The cross section design of the nanostripe allows the tailoring of the static and dynamic response to a certain extent. From a dynamical point of view, the motion induced by the stress differs from known motion regimes because the shape of the domain wall exhibits a remarkable out-of-plane excursion of the magnetization. While we get velocities comparable to those of other techniques, this approach is much more efficient in terms of energy consumption.

HAL (Le Centre pour la Communication Scientifique Directe), Jun 5, 2011

International audienc

HAL (Le Centre pour la Communication Scientifique Directe), 2014

HAL (Le Centre pour la Communication Scientifique Directe), May 26, 2019

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.

HAL (Le Centre pour la Communication Scientifique Directe), Mar 20, 2018

Physical Review Applied, 2020

In this work, we propose a theoretical and experimental investigation of the interaction of guide... more In this work, we propose a theoretical and experimental investigation of the interaction of guided pure shear horizontal (SH) wave within a uniaxial multilayered TbCo2/FeCo thin film deposited on Quartz ST-90°X cut in a delay line configuration. We evaluate theoretically the evolution of phase velocity as a function of magnetic field and experimentally the variation of S21 transmission coefficient (amplitude and phase). An equivalent piezomagnetic model based on pure magnetoelastic coupling was used (developed allowing us) to calculate the elastic stiffness constants of the multilayer as a function of the bias magnetic field. The model was also implemented for acoustic waves dispersion curves calculation. We show that the evolution of the phase velocity with respect to the bias magnetic field is dominated by the C66 elastic stiffness constant as expected for the case of shear horizontal surface acoustic wave. In the fabricated device, both fundamental and third harmonic shear mode are excited at 410 MHz and 1.2 GHz, respectively. For both modes, the theoretical and experimental results are in agreement. At 1.2 GHz the guiding of the acoustic wave in the ferromagnetic thin film enhances the sensitivity to the bias magnetic field with a maximum phase velocity shift close to 2.5 % and an attenuation reaching 500 dB/cm, for a sensitivity as high as 250 ppm/Oe, which is better than what has been reported in literature so far. We also report that, from a specific ratio between the thin film thickness and the acoustic wavelength, the bias magnetic field can induce a breaking of the acoustic wave polarization, leading to an acoustic mode conversion.

Bulletin of the Russian Academy of Sciences: Physics, 2020

Results are presented from an experimental study of the equilibrium distribution of magnetization... more Results are presented from an experimental study of the equilibrium distribution of magnetization and processes of magnetization reversal of magnetoelastic nanostructures in the form of strips with constant or variable width. It is shown that the symmetry of the stable magnetization states in the nanostrip can be broken by a static magnetic field applied perpendicular to the ferromagnet's easy axis. A further change in the states of magnetization allows their manipulation (e.g., moving the domain wall) using the homogeneous mechanical effects induced by applying an electric field to the piezoelectric substrate.

Журнал технической физики, 2020

Straintronic principle of nonvolatile magnetoelectric random access memory (MELRAM) draws much at... more Straintronic principle of nonvolatile magnetoelectric random access memory (MELRAM) draws much attention due to the prospects of ultra-low energy consumption in storage devices. The switching of magnetic moments by pulsed deformation of elastically coupled magnetic and piezoelectric subsystems is accompanied by excitation of acoustic oscillations in the memory cells. Oscillation period in nanoscale cells is comparable with the magnetic moment switching time, which can affect the information recording process. In the present paper the influence of acoustic excitations on the magnetic switching dynamics is studied by numerical modeling with application to a magnetostrictive cell 50×50×400 nm3 on a PMN-PT <011> substrate. Parameters of voltage control pulses that can insure reliable switching of magnetic states of the system are determined.

SPIN, 2019

The Magneto-Optic Kerr Effect (MOKE) technique has been used to investigate the magnetic properti... more The Magneto-Optic Kerr Effect (MOKE) technique has been used to investigate the magnetic properties of Ni thin films, with thickness [Formula: see text] ranging from 9 to 163[Formula: see text]nm, evaporated onto several substrates (glass, Si (111), mica and Cu) with and without an evaporated Cu underlayer. The MOKE observations were correlated with the surface morphology inferred from Scanning Electron Microscope images and with the structural properties (grain size and strain). Some interesting behaviors of the coercive field (with values in the 2 to 151 Oe range), the squareness (between 0.1 and 0.91) and the saturation field (25–320 Oe) are observed as a function of [Formula: see text], the substrate and the Cu underlayer. A thickness-dependent stress-induced anisotropy is found in these films. The differences between the present MOKE results and the ones obtained from the Vibrating Sample magnetometer (VSM) are highlighted. The former describe the surface magnetism of these sys...

John Wiley & Sons, Ltd eBooks, Feb 5, 2016

As the need for energy efficient data processing and data storage booms, numerous efforts are mad... more As the need for energy efficient data processing and data storage booms, numerous efforts are made by research laboratories and industrials to develop the next generation of random access memories. In a 2013 report on emerging technologies to prepare for the post-CMOS era, the International Technology Roadmap for Semiconductors underlines the necessity to "Identify the most promising technical approach(es) to obtain electrically accessible, high-speed, highdensity, low-power, (preferably) embeddable volatile and nonvolatile memories" [1]. In 2009, Mark Kryder and Chang Soo Kim compared the different existing approaches and technologies for the next generation [2]. They described the following solutions: ferroelectric random access memory (FRAM), magnetic memory (MRAM), spin torque transfer magnetic memory (STTRAM), phase change memory (PCRAM), carbon nanotube memory (NRAM), probe memories, holographic memory, conductive bridge memory (CBRAM), resistive memory (RRAM), racetrack memory, one electron memory (SEM), molecular memory and polymer memory. Among all these, the authors argued that only RRAM, CBRAM STTRAM and PCRAM seemed to be viable in the long run. The 2013 ITRS report confirmed this analysis and added carbon-based devices as well as Mott memories to the list of emerging technologies. Both studies are omitting the use of multiferroic materials, possessing coupled ferroelectric Nanomagnetic and Spintronic Devices for Energy-Efficient Memory and Computing, First Edition. Edited by Jayasimha Atulasimha and Supriyo Bandyopadhyay.

Fizika tverdogo tela, 2020

Исследованы магнитные свойства и ферромагнитный резонанс в гетероструктуре, состоящей из эпитакси... more Исследованы магнитные свойства и ферромагнитный резонанс в гетероструктуре, состоящей из эпитаксиальной пленки железо-иттриевого граната (Y 3 Fe5O 12) и редкоземельной интерметаллической сверхрешетки нанометровой толщины, представляющая собой обменно-связанные слои (TbCo 2 /FeCo)n. Сверхрешетка (TbCo 2 /FeCo)n обеспечивает гигантскую магнитострикцию и управляемую наведенную магнитную анизотропию, индуцированную магнитным полем или упругими напряжениями. Было экспериментально обнаружено магнитное взаимодействие пленок в гетероструктуре (TbCo 2 /FeCo)n/Y 3 Fe5O 12 и зарегистрирован спиновый ток, протекающий через их границу.

HAL (Le Centre pour la Communication Scientifique Directe), 2009

Journal of Magnetism and Magnetic Materials, Aug 1, 2018

Stress-mediated magnetoelectric heterostructures represent a very promising approach for the real... more Stress-mediated magnetoelectric heterostructures represent a very promising approach for the realization of ultra-low energy Random Access Memories. The magnetoelectric writing of information has been extensively studied in the past, but it was demontrated only recently that the magnetoelectric effect can also provide means for reading the stored information. We hereby theoretically study the dynamic behaviour of a magnetoelectric random access memory cell (MELRAM) typically composed of a magnetostrictive multilayer N × (TbCo 2 /FeCo) that is elastically coupled with a <011> PMN-PT ferroelectric crystal and placed in a Wheatstone bridge-like configuration. The numerical resolution of the LLG and electrodynamics equation system demonstrates high speed write and read operations with an associated extra-low energy consumption. In this model, the reading energy for a 50nm cell size is estimated to be less than 5 aJ/bit.

Physical review applied, Apr 13, 2022

Electrical control of conjugate degrees of freedom in multiferroics provides the advantage of red... more Electrical control of conjugate degrees of freedom in multiferroics provides the advantage of reducing energy consumption to femto-and even attojoules per switch in spintronics and memory devices. This is achieved through the development of technologies that make it possible to fabricate artificial materials with constantly improving properties. Here, we present the design, physics, and characteristics of a composite multiferroic spintronic emitter, which provides electrical control of the emitted terahertz (THz) wave polarization. The effect is due to electrical control of the magnetization in a high-quality magnetostrictive superlattice, TbCo2/FeCo, deposited on an anisotropic piezoelectric substrate. In our approach, several mechanisms are realized in the system simultaneously: the strain-mediated coupling of the magnetic and piezoelectric subsystems, which operate in the range of the spin-reorientation transition of the magnetic superlattice, and THz-wave generation in the superlattice by an optical femtosecond pulse. This provides flexibility and control of the set of parameters. We determine the magnetoelectric parameter, which is responsible for THz polarization control. Our results offer a significant fundamental insight into the physics of composite multiferroic systems that can be used for applications of multiferroicity, primarily for THz spintronic emitters. We believe that our findings represent a decisive step towards technologies for other types of spintronic and memory devices.

Ferroelectrics, Aug 18, 2018

HAL (Le Centre pour la Communication Scientifique Directe), May 12, 2011

International audienc

HAL (Le Centre pour la Communication Scientifique Directe), Mar 20, 2018

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.

HAL (Le Centre pour la Communication Scientifique Directe), Dec 23, 2011

HAL (Le Centre pour la Communication Scientifique Directe), 2013

HAL (Le Centre pour la Communication Scientifique Directe), Aug 28, 2017

domain wall motion induced by mechanical stress. In our simulations based on an ad-hoc procedure,... more domain wall motion induced by mechanical stress. In our simulations based on an ad-hoc procedure, a magnetoelastic nanostripe comprising two domains is coupled to a <011> cut PMN-PT piezoelectric substrate. The cross section design of the nanostripe allows the tailoring of the static and dynamic response to a certain extent. From a dynamical point of view, the motion induced by the stress differs from known motion regimes because the shape of the domain wall exhibits a remarkable out-of-plane excursion of the magnetization. While we get velocities comparable to those of other techniques, this approach is much more efficient in terms of energy consumption.

HAL (Le Centre pour la Communication Scientifique Directe), Jun 5, 2011

International audienc

HAL (Le Centre pour la Communication Scientifique Directe), 2014

HAL (Le Centre pour la Communication Scientifique Directe), May 26, 2019

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.

HAL (Le Centre pour la Communication Scientifique Directe), Mar 20, 2018

Physical Review Applied, 2020

In this work, we propose a theoretical and experimental investigation of the interaction of guide... more In this work, we propose a theoretical and experimental investigation of the interaction of guided pure shear horizontal (SH) wave within a uniaxial multilayered TbCo2/FeCo thin film deposited on Quartz ST-90°X cut in a delay line configuration. We evaluate theoretically the evolution of phase velocity as a function of magnetic field and experimentally the variation of S21 transmission coefficient (amplitude and phase). An equivalent piezomagnetic model based on pure magnetoelastic coupling was used (developed allowing us) to calculate the elastic stiffness constants of the multilayer as a function of the bias magnetic field. The model was also implemented for acoustic waves dispersion curves calculation. We show that the evolution of the phase velocity with respect to the bias magnetic field is dominated by the C66 elastic stiffness constant as expected for the case of shear horizontal surface acoustic wave. In the fabricated device, both fundamental and third harmonic shear mode are excited at 410 MHz and 1.2 GHz, respectively. For both modes, the theoretical and experimental results are in agreement. At 1.2 GHz the guiding of the acoustic wave in the ferromagnetic thin film enhances the sensitivity to the bias magnetic field with a maximum phase velocity shift close to 2.5 % and an attenuation reaching 500 dB/cm, for a sensitivity as high as 250 ppm/Oe, which is better than what has been reported in literature so far. We also report that, from a specific ratio between the thin film thickness and the acoustic wavelength, the bias magnetic field can induce a breaking of the acoustic wave polarization, leading to an acoustic mode conversion.

Bulletin of the Russian Academy of Sciences: Physics, 2020

Results are presented from an experimental study of the equilibrium distribution of magnetization... more Results are presented from an experimental study of the equilibrium distribution of magnetization and processes of magnetization reversal of magnetoelastic nanostructures in the form of strips with constant or variable width. It is shown that the symmetry of the stable magnetization states in the nanostrip can be broken by a static magnetic field applied perpendicular to the ferromagnet's easy axis. A further change in the states of magnetization allows their manipulation (e.g., moving the domain wall) using the homogeneous mechanical effects induced by applying an electric field to the piezoelectric substrate.

Журнал технической физики, 2020

Straintronic principle of nonvolatile magnetoelectric random access memory (MELRAM) draws much at... more Straintronic principle of nonvolatile magnetoelectric random access memory (MELRAM) draws much attention due to the prospects of ultra-low energy consumption in storage devices. The switching of magnetic moments by pulsed deformation of elastically coupled magnetic and piezoelectric subsystems is accompanied by excitation of acoustic oscillations in the memory cells. Oscillation period in nanoscale cells is comparable with the magnetic moment switching time, which can affect the information recording process. In the present paper the influence of acoustic excitations on the magnetic switching dynamics is studied by numerical modeling with application to a magnetostrictive cell 50×50×400 nm3 on a PMN-PT <011> substrate. Parameters of voltage control pulses that can insure reliable switching of magnetic states of the system are determined.

SPIN, 2019

The Magneto-Optic Kerr Effect (MOKE) technique has been used to investigate the magnetic properti... more The Magneto-Optic Kerr Effect (MOKE) technique has been used to investigate the magnetic properties of Ni thin films, with thickness [Formula: see text] ranging from 9 to 163[Formula: see text]nm, evaporated onto several substrates (glass, Si (111), mica and Cu) with and without an evaporated Cu underlayer. The MOKE observations were correlated with the surface morphology inferred from Scanning Electron Microscope images and with the structural properties (grain size and strain). Some interesting behaviors of the coercive field (with values in the 2 to 151 Oe range), the squareness (between 0.1 and 0.91) and the saturation field (25–320 Oe) are observed as a function of [Formula: see text], the substrate and the Cu underlayer. A thickness-dependent stress-induced anisotropy is found in these films. The differences between the present MOKE results and the ones obtained from the Vibrating Sample magnetometer (VSM) are highlighted. The former describe the surface magnetism of these sys...