Semiconducting properties of nonstoichiometric manganese silicides
Semiconducting properties of nonstoichiometric manganese silicides
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DOI：
10.1007/bf02403407
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发表时间：
1972-04
影响因子：
4.5
通讯作者：
I. Nishida
中科院分区：
文献类型：
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作者：
I. Nishida
在80 ~ 1100 K温度范围内测量了MnSi 2 − x（x = 0.25 ~ 0.28）硅化锰的电阻率、霍尔系数和热电势。在较高的温度下，从电阻率数据估计的禁能隙为约0.40 eV。证实了MnSi 2 − x是简并半导体，并且简并态的空穴浓度在1.8 ~ 2.3× 1021 cm −3之间变化。电子与空穴迁移率之比小于1。本征电阻率和空穴迁移率随温度的变化分别为3.6×10 - 4 exp（2320/T）和1.2× 10 - 4 T-3/2。用迁移率比为0.02计算的霍尔系数值与本征区的结果吻合得很好。根据室温附近MnSi 1.73的空穴浓度与热电势的关系，估算出空穴的有效质量约为自由电子质量的12倍.在假设载流子的散射主要是声晶格散射和载流子服从Fermi-Dirac统计的基础上，计算了热电功率。在150 ~ 1100 K温度范围内，计算结果与实测热电功率符合较好。
Electrical resistivity, Hall coefficient and thermoelectric power were measured on manganese silicides of composition MnSi2−xwithxranging from 0.25 to 0.28 in the temperature range from 80 to 1100K. At higher temperatures a forbidden energy gap estimated from the resistivity data was about 0.40 eV. It was confirmed that MnSi2−xwas a degenerated semiconductor and that the hole concentrations in the degenerated state varied from 1.8 to 2.3×1021cm−3. The ratio of electron to hole mobility was less than unity. The intrinsic resistivity and the hole mobility varied with temperature as 3.6×10−4exp(2320/T) and 1.2×104T−3/2respectively. The value of Hall coefficient calculated by using a mobility ratio of 0.02 was in good agreement with that observed in the intrinsic region. From the relationship between hole concentration and thermoelectric power for MnSi1.73near room temperature, the hole effective mass was estimated to be twelve times as large as the free electron mass. The calculation of the thermoelectric power was carried out based on the assumptions that the scattering of carriers is dominated by acoustic lattice scattering and that the carriers obey Fermi-Dirac statistics. The calculated results were in reasonable agreement with the observed thermoelectric powers in the temperature range from 150 to 1100K.