Crystal structure and thermoelectric properties of partially-substituted melt-grown higher manganese silicides
Crystal structure and thermoelectric properties of partially-substituted melt-grown higher manganese silicides
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DOI：
10.35848/1347-4065/ab709e
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发表时间：
2020-03
影响因子：
1.5
通讯作者：
Y. Miyazaki
中科院分区：
文献类型：
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作者：
Y. Miyazaki
综述了几种部分取代高锰硅化物(HMSS)样品的晶体结构和热电性能。γ具有独特的无公度晶体结构，由[Mn]和[Si]两个子系统组成，其结构式因此被表示为MnSi HMS。C轴长度比γ随温度变化而产生单硅化物(单硅化物)条纹，从而降低机械强度和导电性。少量的V取代有效地消除了这种条纹，提高了空穴载流子浓度。这样制备的V取代样品具有最高的功率因数和显著的较低的导热系数。这种样品的纳米结构由规则的高度无序的硅原子纳米域组成，这将进一步降低热导率，从而提高热电优值。
Crystal structure and thermoelectric properties of several partially-substituted higher manganese silicides (HMSs) samples have been reviewed. HMSs possess a unique incommensurate crystal structure consisting of two subsystems of [Mn] and [Si] and the structure formula is thus represented as MnSiγ. The c-axis length ratio, γ, changes with temperature to yield the MnSi (monosilicide) striations, which deteriorate mechanical strength and electrical conductivity. A small amount of V-substitution effectively dissipates such striations and enhances hole carrier concentration. Thus prepared V-substituted samples exhibit the highest power factor and remarkably lower thermal conductivity. The nanostructure of such samples consists of regular and highly disordered nano-domains of Si atoms, which would further reduce the thermal conductivity to enhance thermoelectric figure-of-merit.