From phase-change materials to thermoelectrics?
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Abstract
Metastable tellurides play an important role as phase-change materials in data storage media and non-vol atile RAM devices. The corresponding crystalline phases with very simple basic structures are not stable as bulk materials at ambient conditions, however, for a broad range of compositions they represent stable high-temperature phases. In the system Ge/Sb/Te, rocksalt-type high-temperature phases are characterized by a large number of vacancies randomly distributed over the cation position, which order as 2D vacancy layers upon cooling. Short-range order in quenched samples produces pronounced nanostructures by the formation of twin domains and finite intersecting vacancy layers. As phase-change materials are usually semimetals or small-bandgap semiconductors and efficient data storage requires low thermal conductivity, bulk materials with similar compositions and properties can be expected to exhibit promising thermoelectric characteristics. Nanostructuring by phase transitions that involve partial vacany ordering may enhance the efficiency of such thermoelectrics. We have shown that germanium antimony tellurides with compositions close to those used as phase-change materials in rewritable Blu-Ray Discs, e.g. (GeTe)12Sb2Te3, exhibit thermoelectric figures of merit of up to ZT = 1.3 at 450 °C if a nanodomain structure is induced by rapidly quenching the cubic high-temperature phase. Structural changes have been elucidated by X-ray diffraction and high-resolution electron microscopy.
© by Oldenbourg Wissenschaftsverlag, Munich, Germany
Articles in the same Issue
- Preface: 3rd International Symposium on Structure-Property Relationships in Solid State Materials (SPSSM-2010)
- Structures and negative thermal expansion properties of the one-dimensional cyanides, CuCN, AgCN and AuCN
- From phase-change materials to thermoelectrics?
- Effect of chromium disorder on the thermoelectric properties of Layered-antiferromagnet CuCrS2
- Copper mobility in CuFeS2, a layered trigonal phase obtained from LiCuFeS2
- Local structure of TiNiCu(Hf) shape memory alloys: XAFS data analysis
- Ce valence in intermetallic compounds by means of XANES spectroscopy
- Correlation of the local and the macroscopic properties of high-temperature superconductors
- Coexistence of Charge Density Waves and d-Wave Superconductivity in Cuprates. Sharing of the Fermi Surface
- The coherent state and its relation to the flat/steep band model
- The layered ferromagnet Cs2AgF4: Antiferromagnetic inter-layer coupling driven by magnetic dipole-dipole interactions
- High-spin to Intermediate-spin Transition, Insulator-metal Transition, and Antiferro- to Ferromagnetic Transition in SrFeO2 under High Pressure
- Pressure effects on energy gaps and phase transitions in ZnAl2Se4
- The effect of pressure on the structural and electronic properties of yttrium orthovanadate YVO4 compound: total-energy calculations
- Relationship between microstructure and photocatalytic properties of nanomaterials
- Semiconductor photocatalysts for the visible light absorption from wide-gap semiconductors with dopant modification
- Filled platinum germanium skutterudites MPt4Ge12 (M = Sr, Ba, La—Nd, Sm, Eu): crystal structure and chemical bonding
Articles in the same Issue
- Preface: 3rd International Symposium on Structure-Property Relationships in Solid State Materials (SPSSM-2010)
- Structures and negative thermal expansion properties of the one-dimensional cyanides, CuCN, AgCN and AuCN
- From phase-change materials to thermoelectrics?
- Effect of chromium disorder on the thermoelectric properties of Layered-antiferromagnet CuCrS2
- Copper mobility in CuFeS2, a layered trigonal phase obtained from LiCuFeS2
- Local structure of TiNiCu(Hf) shape memory alloys: XAFS data analysis
- Ce valence in intermetallic compounds by means of XANES spectroscopy
- Correlation of the local and the macroscopic properties of high-temperature superconductors
- Coexistence of Charge Density Waves and d-Wave Superconductivity in Cuprates. Sharing of the Fermi Surface
- The coherent state and its relation to the flat/steep band model
- The layered ferromagnet Cs2AgF4: Antiferromagnetic inter-layer coupling driven by magnetic dipole-dipole interactions
- High-spin to Intermediate-spin Transition, Insulator-metal Transition, and Antiferro- to Ferromagnetic Transition in SrFeO2 under High Pressure
- Pressure effects on energy gaps and phase transitions in ZnAl2Se4
- The effect of pressure on the structural and electronic properties of yttrium orthovanadate YVO4 compound: total-energy calculations
- Relationship between microstructure and photocatalytic properties of nanomaterials
- Semiconductor photocatalysts for the visible light absorption from wide-gap semiconductors with dopant modification
- Filled platinum germanium skutterudites MPt4Ge12 (M = Sr, Ba, La—Nd, Sm, Eu): crystal structure and chemical bonding
