Thermal Conductivity Measurements and Modeling of Phase-Change GST Materials

2007 ◽  
Author(s):  
Yizhang Yang ◽  
Taehee Jeong ◽  
Hendrik F. Hamann ◽  
Jimmy Zhu ◽  
Mehdi Asheghi
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Data Storage ◽  
Flash Memory ◽  
Performance Optimization ◽  
Phase Change Materials ◽  
Memory Cell ◽  
Data Access ◽  
Optical Recording ◽  
Access Time

Phase-change technology has been widely used in rewritable disks for optical recording applications. Recently, it has also received attention as a candidate for future high storage density non-volatile random access memory, due to its much longer cycle life (∼1013) and fast data access time (∼100ns) compared with the existing Flash memory technology. In this paper, we present thermal conductivity data and models for phase-change GeSbTe material that would be helpful in performance optimization and improvement in the reliability (i.e., enhancement of data rate, cyclability, control of mark-edge jitter) of phase-change-based data storage devices and systems. We perform the thermal characterization of Ge4Sb1Te5 and Ge2Sb2Te5 phase-change materials for the application of optical recording and phase-change memory cell using the techniques of thermoreflectance and electrical resistance thermometry. The limits of lattice and electronic thermal conductivities are investigated to determine their relative contributions as a function of tellurium concentration at different crystalline structures.

scholarly journals Lattice Thermal Conductivity of mGeTe•nSb2Te3 Phase-Change Materials: A First-Principles Study

Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 136 ◽  
Author(s):  
Yuanchun Pan ◽  
Zhen Li ◽  
Zhonglu Guo
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Data Storage ◽  
First Principles ◽  
Phase Change Materials ◽  
Lattice Thermal Conductivity ◽  
Transport Theory ◽  
Large Contribution ◽  
Thermal Transport Property ◽  
Boltzmann Transport Theory

As the most promising materials for phase-change data storage, the pseudobinary mGeTe•nSb2Te3 (GST) chalcogenides have been widely investigated. Nevertheless, an in-depth understanding of the thermal-transport property of GST is still lacking, which is important to achieve overall good performance of the memory devices. Herein, by using first-principles calculations and Boltzmann transport theory, we have systematically studied the lattice thermal conductivity along the out of plane direction of both stable hexagonal and meta-stable rock-salt-like phases of GST, and good agreement with available experiments has been observed. It is revealed that with the increase of the n/m ratio, the lattice thermal conductivity of hexagonal GST increases due to the large contribution from the weak Te-Te bonding, while an inverse trend is observed in meta-stable GST, which is due to the increased number of vacancies that results in the decrease of the lattice thermal conductivity. The size effect on thermal conductivity is also discussed. Our results provide useful information to manipulate the thermal property of GST phase-change materials.

Phase-Change Media for High-Density Optical Recording

2001 ◽  
Vol 674 ◽  
Author(s):  
Herman Borg ◽  
Martijn Lankhorst ◽  
Erwin Meinders ◽  
Wouter Leibbrandt
Keyword(s):  
Phase Change ◽  
Data Storage ◽  
Laser Heating ◽  
Phase Change Materials ◽  
Optical Storage ◽  
Sputter Deposition ◽  
Optical Recording ◽  
Thermal Design ◽  
Recording Media ◽  
Audio Video

ABSTRACTRewritable optical-storage systems are quickly gaining market share in audio, video and data- storage applications. The development of new rewritable optical-storage formats with higher capacity and data rate critically depends on innovations made to the recording media incorporating so-called phase-change materials. These materials allow reversible switching between a low and high reflective state induced by laser heating. In this paper, we highlight phase-change media aspects as optical and thermal design, sputter-deposition, materials optimization, and the development of new recording strategies. Focus is on the speed race in optical recording.

Thermal Conductivity Measurement of the ZnS-SiO2 Dielectric Films for Optical Data Storage Applications

2004 ◽  
Author(s):  
Chun-Teh Li ◽  
Yizhang Yang ◽  
Sadegh M. Sadeghipour ◽  
Mehdi Asheghi
Keyword(s):  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Phase Change ◽  
Data Storage ◽  
Conductivity Measurement ◽  
Optical Data Storage ◽  
Optical Recording ◽  
Optical Data ◽  
Recording Technology ◽  
Dielectric Layers

The amorphous/crystalline phase formation during writing or erasure of the written marks, in the rewritable phase change (PC) optical recording media, is controlled by the temperature distribution in the media and its variation with time. Temperature distribution, on the other hand, strongly depends on the thermal properties of its constituent layers in particular the ZnS-SiO2 dielectric layer that separates the phase change media from the substrate and aluminum heat sink. The reported values for the thermal conductivity of thin dielectric layers are however limited in the literature. In this manuscript, we report thermal conductivity data for dielectric layers of thickness near 50, 100 and 225 nm using the steady sate Joule-heating and electrical resistance thermometry technique. The boundary resistance at the interface is estimated to be near 7.0×10−8 m2 K W−1, which would limit the thermal time constant for cooling of PC layer and potentially impact data rate and jitter in optical recording technology.

Optimization of thermal conductivity in composites loaded with the solid-solid phase-change materials

2018 ◽  
Vol 25 (6) ◽  
pp. 1157-1165
Author(s):  
Taoufik Mnasri ◽  
Adel Abbessi ◽  
Rached Ben Younes ◽  
Atef Mazioud
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Phase Change Materials ◽  
Solid Phase ◽  
Spherical Inclusions ◽  
First Case ◽  
The Matrix ◽  
Composite Conductivity ◽  
First Time

AbstractThis work focuses on identifying the thermal conductivity of composites loaded with phase-change materials (PCMs). Three configurations are studied: (1) the PCMs are divided into identical spherical inclusions arranged in one plane, (2) the PCMs are inserted into the matrix as a plate on the level of the same plane of arrangement, and (3) the PCMs are divided into identical spherical inclusions arranged periodically in the whole matrix. The percentage PCM/matrix is fixed for all cases. A comparison among the various situations is made for the first time, thus providing a new idea on how to insert PCMs into composite matrices. The results show that the composite conductivity is the most important consideration in the first case, precisely when the arrangement plane is parallel with the flux and diagonal to the entry face. In the present work, we are interested in exploring the solid-solid PCMs. The PCM polyurethane and a wood matrix are particularly studied.

scholarly journals The Route for Ultra-High Recording Density Using Probe-Based Data Storage Device

NANO ◽  
2015 ◽  
Vol 10 (08) ◽  
pp. 1550118 ◽  
Author(s):  
Lei Wang ◽  
Jing Wen ◽  
CiHui Yang ◽  
Shan Gai ◽  
YuanXiu Peng
Keyword(s):  
Phase Change ◽  
Data Storage ◽  
Electrical Contact ◽  
Crystal Nucleation ◽  
Access Time ◽  
Storage Device ◽  
Electrical Contact Resistance ◽  
Low Energy Consumption ◽  
Modeling Techniques ◽  
Second Period

Phase-change probe memory using Ge2Sb2Te5 has been considered as one of the promising candidates as next-generation data storage device due to its ultra-high density, low energy consumption, short access time and long retention time. In order to utmostly mimic the practical setup, and thus fully explore the potential of phase-change probe memory for 10 Tbit/in2 target, some advanced modeling techniques that include threshold-switching, electrical contact resistance, thermal boundary resistance and crystal nucleation-growth, are introduced into the already-established electrothermal model to simulate the write and read performance of phase-change probe memory using an optimal media stack design. The resulting predictions clearly demonstrate the capability of phase-change probe memory to record 10 Tbit/in2 density under pico Joule energy within micro second period.

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