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You searched for subject:(Germanium Tellurium Glasses). Showing records 1 – 2 of 2 total matches.

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Indian Institute of Science

1. Sreevidya Varma, G. Mechanical, Structural, Thermal and Electrical Studies on Indium and Silver Doped Ge-Te Glasses having Possible PCM Applications.

Degree: 2014, Indian Institute of Science

The Science behind amorphous Chalcogenide materials opened up new technologies in the arena of Phase Change Memories. The Ovonic universal phase change memory is called universal because it can replace flash memory, DRAM and SRAM. These are not only basic computer memory devices but also are becoming the driving force for the ongoing revolutionary growth of cell phones and other mobile devices, which are in desperate need of memory providing higher density, faster speed and lower power consumption. In this thesis, compositional dependence of various properties of different chalcogenide glasses are investigated, to explore the possibility of their application in Phase Change Memories. Efforts are also made to understand the effect of rigidity and extended rigidity transition on the composition dependence of properties investigated. This thesis comprises of 9 chapters; a brief summary is given below. Chapter 1 deals with fundamental aspects of amorphous semiconductors with a particular reference to chalcogenide glasses. The advantages and applications of chalcogenide glasses are also described. Chapter 2 outlines preparation and characterization of the glasses investigated. The sample preparation and various experimental setup used in the present thesis work like Raman Scattering, Nanoindentation, Alternating Differential Scanning Calorimetry (ADSC), Photo-thermal Deflection Spectroscopy (PDS), Electrical Switching are summarized here. Chapter 3 deals with Micro-Raman studies in Ge15Te85-x Inx Glasses. Micro-Raman studies reveal that as-quenched Ge15Te85-xInx samples exhibit two prominent peaks, at 123 and 155 cm-1. In thermally annealed samples, the peaks at 120 cm-1 and 140 cm-1, which are due to crystalline Te, emerge as the strongest peaks. The Raman spectra of polished samples are similar to those of annealed samples, with strong peaks at 123 cm-1 and 141 cm-1. The spectra of lightly polished samples outside the thermally reversing window resemble those of thermally annealed samples; however, the spectra of glasses with compositions in the thermally reversing window resemble those of as-quenched samples. This observation confirms the earlier idea that compositions in the thermally reversing window are non-ageing and are more stable. Chapter 4 explains nanoindentation studies undertaken on Ge15Te85-xInx glasse (1 ≤ x ≤ 11). Nanoindentation studies on Ge15Te85-xInx glasses indicate that the hardness and elastic modulus of these glasses increase with indium concentration. While a pronounced plateau is seen in the elastic modulus in the composition range 3 ≤ x ≤ 7, the hardness exhibits a change in slope at compositions x = 3 and x = 7. Also, the density exhibits a broad maximum in this composition range. The observed changes in the mechanical properties and density are clearly associated with the thermally reversing window in Ge15Te85-xInx glasses in the composition range 3 ≤ x ≤ 7. In addition, a local minimum is seen in density and hardness around x = 9, the chemical threshold of the system. Chapter 5… Advisors/Committee Members: Asokan, S.

Subjects/Keywords: Chalcogenide Glasses; Germanium-Tellurium Glasses; Phase Change Memory; Chalcogenide Phase Change Memory; Indium Germanium-Tellurium Glasses; Silver Germanium-Tellurium Glasses; Amorphous Semiconductors; Ge-Te Indium Glasses; Ge-Te-In Glasses; Ge-Te Glasses; Ge15Te85-xInx Glasses; Ge15Te80-xIn5Agx Glasses; Materials Science

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APA (6th Edition):

Sreevidya Varma, G. (2014). Mechanical, Structural, Thermal and Electrical Studies on Indium and Silver Doped Ge-Te Glasses having Possible PCM Applications. (Thesis). Indian Institute of Science. Retrieved from http://hdl.handle.net/2005/3080

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Sreevidya Varma, G. “Mechanical, Structural, Thermal and Electrical Studies on Indium and Silver Doped Ge-Te Glasses having Possible PCM Applications.” 2014. Thesis, Indian Institute of Science. Accessed January 22, 2020. http://hdl.handle.net/2005/3080.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Sreevidya Varma, G. “Mechanical, Structural, Thermal and Electrical Studies on Indium and Silver Doped Ge-Te Glasses having Possible PCM Applications.” 2014. Web. 22 Jan 2020.

Vancouver:

Sreevidya Varma G. Mechanical, Structural, Thermal and Electrical Studies on Indium and Silver Doped Ge-Te Glasses having Possible PCM Applications. [Internet] [Thesis]. Indian Institute of Science; 2014. [cited 2020 Jan 22]. Available from: http://hdl.handle.net/2005/3080.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Sreevidya Varma G. Mechanical, Structural, Thermal and Electrical Studies on Indium and Silver Doped Ge-Te Glasses having Possible PCM Applications. [Thesis]. Indian Institute of Science; 2014. Available from: http://hdl.handle.net/2005/3080

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Indian Institute of Science

2. Vinod, E M. Investigations of Phase Change Memory Properties of Selenium Doped GeTe and Ge2Sb2Te5.

Degree: 2013, Indian Institute of Science

GeTe and Ge2Sb2Te5 alloys are potential candidates for non-volatile phase change random access memories (PCRAM). For electrical data storage applications the materials should have stable amorphous and crystalline phases, fast crystallization time, low power to switch, and high crystallization activation energy (to be stable at normal operating temperatures). Phase change memories can be tuned through compositional variations to achieve sufficient phase change contrast and thermal stability for data retention. Selenium is one of the attractive choices to use as an additive material owing to its flexible amorphous structure and a variety of possible applications in optoelectronics and solar cells. GeSb2Te3Se alloy, in which 25 at.% of Se substituted for Te, show a higher room temperature resistance with respect to parent GeSb2Te4 alloy, but the transition temperature is lowered which will affect the thermal stability. The RESET current observed for Sb65Se35 alloys were reduced and the crystallization speed increased 25 % faster with respect to Ge2Sb2Te5. Alloys of Ga-Sb-Se possess advantages such as higher crystallization temperatures, better data retention, higher switching speed, lower thermal conductivity and lower melting point than the GST, but the resistance ratio is limited to about two orders of magnitude. This affects the resistance contrast and data readability. It is with this background a study has been carried out in GeTe and GeSbTe system with Se doping. Studies on structural, thermal and optical properties of these materials all through the phase transition temperatures would be helpful to explore the feasibility of phase change memory uses. Thin films along with their bulk counterparts such as (GeTe)1-x Sex ( 0 < x ≤ 0.50) and (GST)1-xSex (0 < x ≤ 0.50), including GeTe and GST alloys, have been prepared. The results are presented in four chapters apart from the Introduction and Experimental techniques chapters. The final chapter summarizes the results. Chapter 1 provides an introduction to chalcogenide glasses, phase change memory materials and their applications. The fundamental properties of amorphous solids, basic phase change properties of Ge2Sb2Te5 and GeTe alloys and their applications are presented in detail. Various doping studies on GeTe and Ge2Sb2Te5 reported in literatures are reviewed. The limitations, challenges, future and scope of the present work are presented. In chapter 2, the experimental techniques used for thin film preparation, electrical characterizations, optical characterization and surface characterizations etc. are explained. Chapter 3 deals entirely on Ge2Sb2Te5 films studied throughout the phase transition, by annealing at different temperatures. Changes in sheet resistance, optical transmission, morphology and surface bonding characteristics are analyzed. The crystallization leads to an increase of roughness and the resistance changes to three orders of magnitude at 125 °C. Optical studies show distinct changes in transmittance during phase transitions and the optical… Advisors/Committee Members: Sangunni, K S.

Subjects/Keywords: Amorphous Solids; Phase Change Memory Alloys; Germanium-Tellurium Phase Change Memory Alloys; Germanium-Antimony-TelluriumPhase Change Memory Alloys; Amorphous Semiconductors; Selenium Doped GeTe Alloys; Selenium Doped GeSbTe Alloys; Chalcogenide Glasses; GeTe Thin Films; GST (Germanium-Antimony-Tellurium) Films; Phase Change Random Access Memory; Phase Change Memory Materials; Ge2Sb2Te5 Thin Films; Ge-Te Phase Change Memory Alloys; Ge-Sb-Te Phase Change Memory Alloys; Materials Science

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Vinod, E. M. (2013). Investigations of Phase Change Memory Properties of Selenium Doped GeTe and Ge2Sb2Te5. (Thesis). Indian Institute of Science. Retrieved from http://etd.iisc.ernet.in/2005/3339 ; http://etd.iisc.ernet.in/abstracts/4204/G25733-Abs.pdf

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Vinod, E M. “Investigations of Phase Change Memory Properties of Selenium Doped GeTe and Ge2Sb2Te5.” 2013. Thesis, Indian Institute of Science. Accessed January 22, 2020. http://etd.iisc.ernet.in/2005/3339 ; http://etd.iisc.ernet.in/abstracts/4204/G25733-Abs.pdf.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Vinod, E M. “Investigations of Phase Change Memory Properties of Selenium Doped GeTe and Ge2Sb2Te5.” 2013. Web. 22 Jan 2020.

Vancouver:

Vinod EM. Investigations of Phase Change Memory Properties of Selenium Doped GeTe and Ge2Sb2Te5. [Internet] [Thesis]. Indian Institute of Science; 2013. [cited 2020 Jan 22]. Available from: http://etd.iisc.ernet.in/2005/3339 ; http://etd.iisc.ernet.in/abstracts/4204/G25733-Abs.pdf.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Vinod EM. Investigations of Phase Change Memory Properties of Selenium Doped GeTe and Ge2Sb2Te5. [Thesis]. Indian Institute of Science; 2013. Available from: http://etd.iisc.ernet.in/2005/3339 ; http://etd.iisc.ernet.in/abstracts/4204/G25733-Abs.pdf

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

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