Microwave magnetoplasma study of lattice and electronic properties of PbTe
Microwave magnetoplasma study of lattice and electronic properties of PbTe
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DOI：
10.1103/physrevb.15.4830
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发表时间：
1977-05
影响因子：
3.7
通讯作者：
G. Foley;D. Langenberg
中科院分区：
文献类型：
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作者：
G. Foley;D. Langenberg
用微波磁等离子体实验测定了PbTe中Q=0的横向光学声子频率ωTo，频率在70、138和335 GHz附近，温度范围为4.2≤T≲80K。在最低温度下，ωto几乎与温度无关，其值为12.3±1.0 cm−1。这意味着，通过Lydane-Sachs-Teller关系，静态晶格介电常数εS≅3000，取决于假设的高频介电常数ε∞的值。在30K以上，ωto呈现出与居里定律一致的静态晶格介电常数εS∝(T−TC)−1的温度依赖关系。居里温度在-15 0K和-80K附近，但较好的实验值是TC=−15 1±7K，并测定了几个带边电参数：横向导电带边有效质量，m1cm0=0.0164±0.001；横向价带边缘有效质量，m1vm0=0.021±0.001；价带边缘质量各向异性比，K0v=13.4±2.0.讨论了样品制备和表征程序的关键重要性，以及以前报道的εS的值之间存在差异的可能原因，这些值分散在两个数量级上。
The q= 0 transverse-optic-phonon frequency ω TO has been determined in PbTe from microwave magnetoplasma experiments at frequencies near 70, 138, and 335 GHz, over the temperature range 4.2≤ T≲ 80 K. Both n-type and p-type bulk samples and p-type epitaxial thin films on Ba F 2 substrates were studied. At the lowest temperatures, ω TO is almost temperature independent and has the value 12.3±1.0 cm− 1. This implies, via the Lyddane-Sachs-Teller relation, a static lattice dielectric constant ε s≅ 3000, depending on the value assumed for the high-frequency dielectric constant ε∞. At temperatures above 30 K, ω TO shows a temperature dependence which is consistent with Curie-law behavior of the static lattice dielectric constant, ε s∝(T− T C)− 1. Curie temperatures near both-150 and-80 K were found, but the favored experimental value is T C=− 151±7 K. Several band-edge electronic parameters were also determined: transverse-conduction-band-edge effective mass, m 1 c m 0= 0.0164±0.001; transverse-valence-band-edge effective mass, m 1 v m 0= 0.021±0.001: valence-band-edge mass anisotropy ratio, K 0 v= 13.4±2.0. The critical importance of sample preparation and characterization procedures is discussed, together with possible reasons for the discrepancies among previously reported values of ε s, which scatter over two orders of magnitude.