Gerry Triani - Academia.edu (original) (raw)

Papers by Gerry Triani

Research paper thumbnail of Hydrothermal crystallization of amorphous titania films deposited using low temperature atomic layer deposition

Thin Solid Films, 2008

ABSTRACT A two stage process (atomic layer deposition, followed by hydrothermal treatment) for pr... more ABSTRACT A two stage process (atomic layer deposition, followed by hydrothermal treatment) for producing crystalline titania thin films at temperatures compatible with polymeric substrates (50% of the film had crystallized. Crystallization was complete after 10 days of hydrothermal treatment. Crystallization of the film resulted in the formation of coarse grained anatase. Residual Cl was completely expelled from the film upon crystallization. As a result of the amorphous to crystalline transformation voids formed at the crystallization front. Inward and lateral crystal growth resulted in voids being localized to the film/substrate interface and crystallite perimeters resulting in pinholing. Both these phenomena resulted in films with poor adhesion and film integrity was severely compromised.

Research paper thumbnail of Amorphous to anatase transformation in atomic layer deposited titania thin films induced by hydrothermal treatment at 120 °C

Journal of Materials Research, 2008

ABSTRACT Hydrothermal treatment has been applied successfully to convert amorphous titania films ... more ABSTRACT Hydrothermal treatment has been applied successfully to convert amorphous titania films to crystalline anatase at 120 °C, a temperature compatible with most polymeric substrates. The amorphous films were deposited at 80 °C using atomic layer deposition (ALD). The crystallinity of the films was monitored by x-ray absorption near edge structure (XANES), and the film composition was determined by x-ray photoelectron spectroscopy (XPS). The effect of precursor chemistry and substrate material was investigated. It was found that titania films produced from Ti isopropoxide are easier to crystallize than those from Ti tetrachloride as the Ti precursor. The amorphous to crystalline transformation can be achieved more readily with films deposited on Si than polycarbonate substrates. The effect of a “seed” layer on the amorphous to crystalline transformation was also studied. Preformed anatase crystallites between the Si substrate and the amorphous film were shown to accelerate the crystallization process. The possible mechanisms responsible for the phase transformation are discussed.

Research paper thumbnail of Mechanical stability of a TiO2 coating deposited on a polycarbonate substrate

Research paper thumbnail of Dielectric energy storage in PbxSr1-xTiO3 ceramics

This paper discusses the suitability of PbxSr1-xTiO3 ceramics for application as the dielectric l... more This paper discusses the suitability of PbxSr1-xTiO3 ceramics for application as the dielectric layer in high energy density capacitors. For PbxSr1-xTiO3 ceramics with x = 0.25, and for electric fields greater than 50 kV mm -1, it was found that the composition with x=0.15 was the most favorable for use in high-energy-density capacitors. © 2001 Kluwer Academic Publishers

Research paper thumbnail of Atomic layer deposition (ALD) of TiO2 and Al2O3 thin films on silicon

The essential features of the ALD process involve sequentially saturating a surface with a (sub)m... more The essential features of the ALD process involve sequentially saturating a surface with a (sub)monolayer of reactive species, such as a metal halide, then reacting it with a second species to form the required phase in-situ. Repetition of the reaction sequence allows the desired thickness to be deposited. The self-limiting nature of the reactions ensures excellent conformality, and sequential processing

Research paper thumbnail of Low-Temperature Bonding of Ceramics by Sol-Gel Processing

MRS Proceedings, 1999

Journal of Sol-Gel Science and Technology 19, 321–324, 2000 c 2000 Kluwer Academic Publishers. Ma... more Journal of Sol-Gel Science and Technology 19, 321–324, 2000 c 2000 Kluwer Academic Publishers. Manufactured in The Netherlands. ... Low Temperature Bonding of Ceramics by Sol-Gel Processing ... CJ BARB ´E ∗ , DJ CASSIDY, G. TRIANI, BA LATELLA, DRG ...

Research paper thumbnail of Sol–gel bonding of silicon wafers

Thin Solid Films, 2005

Low temperature bonding of silicon wafers was achieved using sol–gel technology. The initial sol–... more Low temperature bonding of silicon wafers was achieved using sol–gel technology. The initial sol–gel chemistry of the coating solution was found to influence the mechanical properties of the resulting bonds. More precisely, the influence of parameters such as the alkoxide concentration, water-to-alkoxide molar ratio, pH, and solution aging on the final bond morphologies and interfacial fracture energy was studied. The

Research paper thumbnail of Evaluation of interfacial toughness and bond strength of sandwiched silicon structures

Thin Solid Films, 2002

Results of a study to measure the interfacial strength and toughness in sandwiched silicon struct... more Results of a study to measure the interfacial strength and toughness in sandwiched silicon structures, using sol-gel processing as the bonding method, are examined. The interfacial bond strength was determined using a standard uniaxial tensile test, while a relative measure of interface toughness was ascertained using exploratory Vickers indentations. The specimens were positioned and aligned so that the indentations were made directly on the interface region, with the cracks emanating from one set of the impression diagonals at the free surface coinciding with the trace of the interface. The length of these radial cracks, having a penny-like configuration, required to cause debonding at the interface was measured in order to provide relative fracture toughness and fracture energy values. Indications of 'local' bond toughness were obtained by indenting at locations near the interface and following the path of the radial cracks. The applicability of the technique with reference to material interfaces is discussed. ᮊ

Research paper thumbnail of Atomic layer deposition of TiO 2 and Al 2 O 3 thin films and nanolaminates

Smart Materials and Structures, 2006

... Atomic layer deposition of TiO2 and Al2O3 thin films and nanolaminates DRG Mitchell, G Triani... more ... Atomic layer deposition of TiO2 and Al2O3 thin films and nanolaminates DRG Mitchell, G Triani, DJ Attard, KS Finnie, PJ Evans, CJ Barbé and JR Bartlett Institute of Materials Science and Engineering, ANSTO, PMB 1, Menai, NSW 2234, Australia E-mail: drm@ansto.gov.au ...

Research paper thumbnail of Crystallization of TiO 2 Powders and Thin Films Prepared from Modified Titanium Alkoxide Precursors

Journal of the American Ceramic Society, 2008

. AFM images of (a) TiP-and (b) [6,4]-derived films after annealing at 8001C for 1 h. Scan size i... more . AFM images of (a) TiP-and (b) [6,4]-derived films after annealing at 8001C for 1 h. Scan size is 5 mm  5 mm.

Research paper thumbnail of Alkaline hydrothermal kinetics in titanate nanostructure formation

Journal of Materials Science, 2011

In this study, the mechanism of precursor dissolution and the influence of kinetics of dissolutio... more In this study, the mechanism of precursor dissolution and the influence of kinetics of dissolution on titanate nanotube formation were investigated. This comparative study explored the dissolution kinetics for the case of commercial titania powders, one composed of predominantly anatase ([95%) and the other rutile phase ([93%). These nanoparticle precursors were hydrothermally reacted in 9 mol L -1 NaOH at 160°C over a range of reaction times of between 2 and 32 h. The high surface area nanotube-form product was confirmed using X-ray diffraction, FT-Raman spectroscopy, and transmission electron microscopy. The concentration of nanotubes produced from the different precursors was established using Rietveld analysis with internal and external corundum standardization to calibrate the absolute concentrations of the samples. Interpretation of the dissolution process of the precursor materials indicated that the dissolution of anatase proceeds via a zero-order kinetic process, whereas rutile dissolution is through a second-order process. The TiO 2 nanostructure formation process and mechanism of TiO 2 precursor dissolution was confirmed by non-invasive dynamic light scattering measurements. Significant observations are that nanotube formation occurred over a broad range of hydrothermal treatment conditions and was strongly influenced by the order of precursor dissolution.

Research paper thumbnail of Dielectric energy storage densities in Ba 1-x Sr x Ti 1-y Zr y O 3 ceramics

Journal of Materials Science-materials in Electronics - J MATER SCI-MATER ELECTRON, 2000

This paper presents measurements of the Weiss temperature, the Curie constant, the spontaneous po... more This paper presents measurements of the Weiss temperature, the Curie constant, the spontaneous polarization and the stored dielectric energy density of Ba1-xSrxTi1-yZryO3 ceramics for compositions with 0=x=1 and 0=y=0.5. The first three of these dielectric parameters are used to predict the density of energy storage that can be obtained when ceramics of these compositions are used as capacitor dielectrics. These predictions are compared with direct measurements of energy densities which show that for moderate electric field strengths (-50 kV mm -1) the stored dielectric energy densities were the largest for ceramics with x>0.7 and y?~0.2. © 2000 Kluwer Academic Publishers

Research paper thumbnail of TEM and ellipsometry studies of nanolaminate oxide films prepared using atomic layer deposition

Applied Surface Science, 2005

Nanolaminate oxide layers consisting of TiO 2 and Al 2 O 3 have been deposited on silicon using a... more Nanolaminate oxide layers consisting of TiO 2 and Al 2 O 3 have been deposited on silicon using atomic layer deposition (ALD). Characterisation of these films has been achieved by use of a range of modern transmission electron microscopy (TEM)-based techniques, including ...

Research paper thumbnail of Mechanical stability of a TiO2 coating deposited on a polycarbonate substrate

Research paper thumbnail of Atomic layer deposition (ALD) of TiO2 and Al2O3 thin films on silicon

The essential features of the ALD process involve sequentially saturating a surface with a (sub)m... more The essential features of the ALD process involve sequentially saturating a surface with a (sub)monolayer of reactive species, such as a metal halide, then reacting it with a second species to form the required phase in-situ. Repetition of the reaction sequence allows the desired thickness to be deposited. The self-limiting nature of the reactions ensures excellent conformality, and sequential processing

Research paper thumbnail of <title>Characterization of thin metal oxide films grown by atomic layer deposition</title>

Device and Process Technologies for MEMS, Microelectronics, and Photonics III, 2004

Atomic layer deposition (ALD) is a versatile technique for producing a wide variety of thin films... more Atomic layer deposition (ALD) is a versatile technique for producing a wide variety of thin films. It provides a method for precisely controlling film thickness and composition. In addition films produced by ALD are highly conformal and are therefore excellent for the generation of MEMS devices. In the present study, single and multi layer films of TiO2 and Al2O3 have

Research paper thumbnail of ChemInform Abstract: Novel Chemical Synthesis and Characterization of CeTi 2 O 6 Brannerite

Research paper thumbnail of Low-Temperature Bonding of Ceramics by Sol-Gel Processing

MRS Proceedings, 1999

Journal of Sol-Gel Science and Technology 19, 321–324, 2000 c 2000 Kluwer Academic Publishers. Ma... more Journal of Sol-Gel Science and Technology 19, 321–324, 2000 c 2000 Kluwer Academic Publishers. Manufactured in The Netherlands. ... Low Temperature Bonding of Ceramics by Sol-Gel Processing ... CJ BARB ´E ∗ , DJ CASSIDY, G. TRIANI, BA LATELLA, DRG ...

Research paper thumbnail of Sol–gel bonding of silicon wafers

Thin Solid Films, 2005

Low temperature bonding of silicon wafers was achieved using sol–gel technology. The initial sol–... more Low temperature bonding of silicon wafers was achieved using sol–gel technology. The initial sol–gel chemistry of the coating solution was found to influence the mechanical properties of the resulting bonds. More precisely, the influence of parameters such as the alkoxide concentration, water-to-alkoxide molar ratio, pH, and solution aging on the final bond morphologies and interfacial fracture energy was studied. The

Research paper thumbnail of Transmission electron microscopy studies of atomic layer deposition TiO2 films grown on silicon

Thin Solid Films, 2003

Transmission electron microscopy techniques have been used to characterise atomic layer depositio... more Transmission electron microscopy techniques have been used to characterise atomic layer deposition TiO films grown on 2 silicon substrates after RCA and HF treatment. The influence of deposition temperature (250-350 8C) and substrate type on the film microstructure have been determined. The major influence of substrate type is to control nucleation of crystallisation. HF treated silicon, which was devoid of the native oxide layer, promoted a crystalline, island growth mode. The nucleation of crystalline particles at the onset of deposition resulted in films with very fine grain sizes (f20 nm). The RCA treated silicon, which was coated with amorphous native oxide, caused the growth of an initially amorphous TiO film, which crystallised once 2 a critical film thickness had been exceeded. The major influence of temperature on the films grown on RCA treated silicon was to control nucleation of crystallisation within the amorphous layers, resulting in grain size refinement at higher deposition temperatures. Under the processing conditions used, other than the transient amorphous films formed on RCA treated silicon, anatase was the only phase formed. No evidence for preferred orientation was found. ᮊ

Research paper thumbnail of Hydrothermal crystallization of amorphous titania films deposited using low temperature atomic layer deposition

Thin Solid Films, 2008

ABSTRACT A two stage process (atomic layer deposition, followed by hydrothermal treatment) for pr... more ABSTRACT A two stage process (atomic layer deposition, followed by hydrothermal treatment) for producing crystalline titania thin films at temperatures compatible with polymeric substrates (50% of the film had crystallized. Crystallization was complete after 10 days of hydrothermal treatment. Crystallization of the film resulted in the formation of coarse grained anatase. Residual Cl was completely expelled from the film upon crystallization. As a result of the amorphous to crystalline transformation voids formed at the crystallization front. Inward and lateral crystal growth resulted in voids being localized to the film/substrate interface and crystallite perimeters resulting in pinholing. Both these phenomena resulted in films with poor adhesion and film integrity was severely compromised.

Research paper thumbnail of Amorphous to anatase transformation in atomic layer deposited titania thin films induced by hydrothermal treatment at 120 °C

Journal of Materials Research, 2008

ABSTRACT Hydrothermal treatment has been applied successfully to convert amorphous titania films ... more ABSTRACT Hydrothermal treatment has been applied successfully to convert amorphous titania films to crystalline anatase at 120 °C, a temperature compatible with most polymeric substrates. The amorphous films were deposited at 80 °C using atomic layer deposition (ALD). The crystallinity of the films was monitored by x-ray absorption near edge structure (XANES), and the film composition was determined by x-ray photoelectron spectroscopy (XPS). The effect of precursor chemistry and substrate material was investigated. It was found that titania films produced from Ti isopropoxide are easier to crystallize than those from Ti tetrachloride as the Ti precursor. The amorphous to crystalline transformation can be achieved more readily with films deposited on Si than polycarbonate substrates. The effect of a “seed” layer on the amorphous to crystalline transformation was also studied. Preformed anatase crystallites between the Si substrate and the amorphous film were shown to accelerate the crystallization process. The possible mechanisms responsible for the phase transformation are discussed.

Research paper thumbnail of Mechanical stability of a TiO2 coating deposited on a polycarbonate substrate

Research paper thumbnail of Dielectric energy storage in PbxSr1-xTiO3 ceramics

This paper discusses the suitability of PbxSr1-xTiO3 ceramics for application as the dielectric l... more This paper discusses the suitability of PbxSr1-xTiO3 ceramics for application as the dielectric layer in high energy density capacitors. For PbxSr1-xTiO3 ceramics with x = 0.25, and for electric fields greater than 50 kV mm -1, it was found that the composition with x=0.15 was the most favorable for use in high-energy-density capacitors. © 2001 Kluwer Academic Publishers

Research paper thumbnail of Atomic layer deposition (ALD) of TiO2 and Al2O3 thin films on silicon

The essential features of the ALD process involve sequentially saturating a surface with a (sub)m... more The essential features of the ALD process involve sequentially saturating a surface with a (sub)monolayer of reactive species, such as a metal halide, then reacting it with a second species to form the required phase in-situ. Repetition of the reaction sequence allows the desired thickness to be deposited. The self-limiting nature of the reactions ensures excellent conformality, and sequential processing

Research paper thumbnail of Low-Temperature Bonding of Ceramics by Sol-Gel Processing

MRS Proceedings, 1999

Journal of Sol-Gel Science and Technology 19, 321–324, 2000 c 2000 Kluwer Academic Publishers. Ma... more Journal of Sol-Gel Science and Technology 19, 321–324, 2000 c 2000 Kluwer Academic Publishers. Manufactured in The Netherlands. ... Low Temperature Bonding of Ceramics by Sol-Gel Processing ... CJ BARB ´E ∗ , DJ CASSIDY, G. TRIANI, BA LATELLA, DRG ...

Research paper thumbnail of Sol–gel bonding of silicon wafers

Thin Solid Films, 2005

Low temperature bonding of silicon wafers was achieved using sol–gel technology. The initial sol–... more Low temperature bonding of silicon wafers was achieved using sol–gel technology. The initial sol–gel chemistry of the coating solution was found to influence the mechanical properties of the resulting bonds. More precisely, the influence of parameters such as the alkoxide concentration, water-to-alkoxide molar ratio, pH, and solution aging on the final bond morphologies and interfacial fracture energy was studied. The

Research paper thumbnail of Evaluation of interfacial toughness and bond strength of sandwiched silicon structures

Thin Solid Films, 2002

Results of a study to measure the interfacial strength and toughness in sandwiched silicon struct... more Results of a study to measure the interfacial strength and toughness in sandwiched silicon structures, using sol-gel processing as the bonding method, are examined. The interfacial bond strength was determined using a standard uniaxial tensile test, while a relative measure of interface toughness was ascertained using exploratory Vickers indentations. The specimens were positioned and aligned so that the indentations were made directly on the interface region, with the cracks emanating from one set of the impression diagonals at the free surface coinciding with the trace of the interface. The length of these radial cracks, having a penny-like configuration, required to cause debonding at the interface was measured in order to provide relative fracture toughness and fracture energy values. Indications of 'local' bond toughness were obtained by indenting at locations near the interface and following the path of the radial cracks. The applicability of the technique with reference to material interfaces is discussed. ᮊ

Research paper thumbnail of Atomic layer deposition of TiO 2 and Al 2 O 3 thin films and nanolaminates

Smart Materials and Structures, 2006

... Atomic layer deposition of TiO2 and Al2O3 thin films and nanolaminates DRG Mitchell, G Triani... more ... Atomic layer deposition of TiO2 and Al2O3 thin films and nanolaminates DRG Mitchell, G Triani, DJ Attard, KS Finnie, PJ Evans, CJ Barbé and JR Bartlett Institute of Materials Science and Engineering, ANSTO, PMB 1, Menai, NSW 2234, Australia E-mail: drm@ansto.gov.au ...

Research paper thumbnail of Crystallization of TiO 2 Powders and Thin Films Prepared from Modified Titanium Alkoxide Precursors

Journal of the American Ceramic Society, 2008

. AFM images of (a) TiP-and (b) [6,4]-derived films after annealing at 8001C for 1 h. Scan size i... more . AFM images of (a) TiP-and (b) [6,4]-derived films after annealing at 8001C for 1 h. Scan size is 5 mm  5 mm.

Research paper thumbnail of Alkaline hydrothermal kinetics in titanate nanostructure formation

Journal of Materials Science, 2011

In this study, the mechanism of precursor dissolution and the influence of kinetics of dissolutio... more In this study, the mechanism of precursor dissolution and the influence of kinetics of dissolution on titanate nanotube formation were investigated. This comparative study explored the dissolution kinetics for the case of commercial titania powders, one composed of predominantly anatase ([95%) and the other rutile phase ([93%). These nanoparticle precursors were hydrothermally reacted in 9 mol L -1 NaOH at 160°C over a range of reaction times of between 2 and 32 h. The high surface area nanotube-form product was confirmed using X-ray diffraction, FT-Raman spectroscopy, and transmission electron microscopy. The concentration of nanotubes produced from the different precursors was established using Rietveld analysis with internal and external corundum standardization to calibrate the absolute concentrations of the samples. Interpretation of the dissolution process of the precursor materials indicated that the dissolution of anatase proceeds via a zero-order kinetic process, whereas rutile dissolution is through a second-order process. The TiO 2 nanostructure formation process and mechanism of TiO 2 precursor dissolution was confirmed by non-invasive dynamic light scattering measurements. Significant observations are that nanotube formation occurred over a broad range of hydrothermal treatment conditions and was strongly influenced by the order of precursor dissolution.

Research paper thumbnail of Dielectric energy storage densities in Ba 1-x Sr x Ti 1-y Zr y O 3 ceramics

Journal of Materials Science-materials in Electronics - J MATER SCI-MATER ELECTRON, 2000

This paper presents measurements of the Weiss temperature, the Curie constant, the spontaneous po... more This paper presents measurements of the Weiss temperature, the Curie constant, the spontaneous polarization and the stored dielectric energy density of Ba1-xSrxTi1-yZryO3 ceramics for compositions with 0=x=1 and 0=y=0.5. The first three of these dielectric parameters are used to predict the density of energy storage that can be obtained when ceramics of these compositions are used as capacitor dielectrics. These predictions are compared with direct measurements of energy densities which show that for moderate electric field strengths (-50 kV mm -1) the stored dielectric energy densities were the largest for ceramics with x>0.7 and y?~0.2. © 2000 Kluwer Academic Publishers

Research paper thumbnail of TEM and ellipsometry studies of nanolaminate oxide films prepared using atomic layer deposition

Applied Surface Science, 2005

Nanolaminate oxide layers consisting of TiO 2 and Al 2 O 3 have been deposited on silicon using a... more Nanolaminate oxide layers consisting of TiO 2 and Al 2 O 3 have been deposited on silicon using atomic layer deposition (ALD). Characterisation of these films has been achieved by use of a range of modern transmission electron microscopy (TEM)-based techniques, including ...

Research paper thumbnail of Mechanical stability of a TiO2 coating deposited on a polycarbonate substrate

Research paper thumbnail of Atomic layer deposition (ALD) of TiO2 and Al2O3 thin films on silicon

The essential features of the ALD process involve sequentially saturating a surface with a (sub)m... more The essential features of the ALD process involve sequentially saturating a surface with a (sub)monolayer of reactive species, such as a metal halide, then reacting it with a second species to form the required phase in-situ. Repetition of the reaction sequence allows the desired thickness to be deposited. The self-limiting nature of the reactions ensures excellent conformality, and sequential processing

Research paper thumbnail of <title>Characterization of thin metal oxide films grown by atomic layer deposition</title>

Device and Process Technologies for MEMS, Microelectronics, and Photonics III, 2004

Atomic layer deposition (ALD) is a versatile technique for producing a wide variety of thin films... more Atomic layer deposition (ALD) is a versatile technique for producing a wide variety of thin films. It provides a method for precisely controlling film thickness and composition. In addition films produced by ALD are highly conformal and are therefore excellent for the generation of MEMS devices. In the present study, single and multi layer films of TiO2 and Al2O3 have

Research paper thumbnail of ChemInform Abstract: Novel Chemical Synthesis and Characterization of CeTi 2 O 6 Brannerite

Research paper thumbnail of Low-Temperature Bonding of Ceramics by Sol-Gel Processing

MRS Proceedings, 1999

Journal of Sol-Gel Science and Technology 19, 321–324, 2000 c 2000 Kluwer Academic Publishers. Ma... more Journal of Sol-Gel Science and Technology 19, 321–324, 2000 c 2000 Kluwer Academic Publishers. Manufactured in The Netherlands. ... Low Temperature Bonding of Ceramics by Sol-Gel Processing ... CJ BARB ´E ∗ , DJ CASSIDY, G. TRIANI, BA LATELLA, DRG ...

Research paper thumbnail of Sol–gel bonding of silicon wafers

Thin Solid Films, 2005

Low temperature bonding of silicon wafers was achieved using sol–gel technology. The initial sol–... more Low temperature bonding of silicon wafers was achieved using sol–gel technology. The initial sol–gel chemistry of the coating solution was found to influence the mechanical properties of the resulting bonds. More precisely, the influence of parameters such as the alkoxide concentration, water-to-alkoxide molar ratio, pH, and solution aging on the final bond morphologies and interfacial fracture energy was studied. The

Research paper thumbnail of Transmission electron microscopy studies of atomic layer deposition TiO2 films grown on silicon

Thin Solid Films, 2003

Transmission electron microscopy techniques have been used to characterise atomic layer depositio... more Transmission electron microscopy techniques have been used to characterise atomic layer deposition TiO films grown on 2 silicon substrates after RCA and HF treatment. The influence of deposition temperature (250-350 8C) and substrate type on the film microstructure have been determined. The major influence of substrate type is to control nucleation of crystallisation. HF treated silicon, which was devoid of the native oxide layer, promoted a crystalline, island growth mode. The nucleation of crystalline particles at the onset of deposition resulted in films with very fine grain sizes (f20 nm). The RCA treated silicon, which was coated with amorphous native oxide, caused the growth of an initially amorphous TiO film, which crystallised once 2 a critical film thickness had been exceeded. The major influence of temperature on the films grown on RCA treated silicon was to control nucleation of crystallisation within the amorphous layers, resulting in grain size refinement at higher deposition temperatures. Under the processing conditions used, other than the transient amorphous films formed on RCA treated silicon, anatase was the only phase formed. No evidence for preferred orientation was found. ᮊ