ELECTRICAL AND MAGNETIC PROPERTIES OF POTASSIUM TUNGSTEN BRONZE AND RUBIDIUM TUNGSTEN BRONZE
ELECTRICAL AND MAGNETIC PROPERTIES OF POTASSIUM TUNGSTEN BRONZE AND RUBIDIUM TUNGSTEN BRONZE
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DOI：
10.1021/ic50007a014
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发表时间：
1963-01-01
影响因子：
4.6
通讯作者：
MACENNES.S
中科院分区：
文献类型：
--
作者：
SIENKO, MJ;MACENNES.S
单晶电导率已被测量为K 0。40 WO 3和Rbo. szWO在150到370 K范围内。载流子迁移率，这是略高于在锂和钠钨青铜，密切遵循T sinh 2（0/2 T）的依赖。基于Howarth和Sondheimer理论的计算有力地支持了钨青铜中载流子迁移率的热部分主要由光模晶格振动的极性散射决定的假设。还在室温下测量了RbcueW 0和K 0的磁化率。23-0.45 WO3。结果与Pauli-Peierls准自由电子理论所预言的一样，钨青铜M^ WOa（0< x< 1）在很宽的组成范围内都具有金属性质，作为研究金属束缚理论的模型系统有着相当大的希望。特别是，传导d带的态密度函数特性的过程似乎可以直接从实验上作为变化的电子浓度的函数。然而，除了立方钠钨青铜和立方锂钨青铜，它们在结构、电导率、磁磁化率、热电动势和霍尔电压方面有相当多的数据，对其他碱钨青铜的观察是零碎的、定性的，有时还相互矛盾。在预期不久有带计算的钨青铜，我们进行了这项调查的钾和铷钨青铜提供典型的非立方青铜的参数。Laurent 4首先通过氢还原K2 WO 4-WO 3混合物制备了钾钨青铜。随后的制备方法包括用锡还原K_2WO_4-WO_3，5熔融K_2WO_4的电解，6用WO_2还原K_2WO_4-WO_3，7和用元素钨还原K_2WO_4-WO_3。[8] Schaefer 9首次用甲烷和氢气还原Rb_2CO_3-H_2WO_4混合物制备了一种特定的铷钨青铜。钾青铜KVWO_3的四电子结构在8· 10 ~ 0.40< x< 0.57范围内，a= 12.285 Ω·cm。和
Single crystal conductivities have been measured for K0. 40WO3 and Rbo. szWOs in the range 150 to 370 K. Carrier mobilities, which are somewhat higher than in the Li and Na tungsten bronzes, closely follow a T sinh2 (0/2 T) dependence. Calculations on the basis of the theory of Howarth and Sondheimer strongly support the assumption that the thermal part of the carrier mobility in the tungsten bronzes is primarily determined by polar scattering from optical mode latticevibrations. Magnetic susceptibilities also have been measured at room temperature for RbcueWOs and K0. 23-0.45 WO3. Results are as predicted by the Pauli-Peierls theory for quasi-free electrons.The tungsten bronzes, M^ WOa (0< x< 1), which have metallic properties2 over a wide range of compo-sition, hold considerable promise as model systems for examining theories of metallic binding. In particular, the course of a density-of-states function characteristic of a conducting d-band seems directly accessible experi-mentally as a function of varying electronconcentra-tion. However, except for the cubic sodium and lithium tungsten bronzes, for which considerable data exist3 on structure, conductivity, magnetic suscepti-bility, thermal emf, and Hall voltage, observations on the other alkali tungsten bronzes are fragmentary, qualitative, and occasionally contradictory. In anticipation of shortly having band calculations for the tung-sten bronzes, we have undertaken this investigation of potassium and of rubidium tungsten bronzes to provide parameters for typical non-cubic bronzes. Potassium tungsten bronzes first were prepared by Laurent4 by reductionof K2WO4-WO3 mixtures with hydrogen. Subsequent preparation methods included reduction of K2WO4-WO3 with tin, 5 electrolysis of fused K2WO4, 6 reduction of K2WO4-WO3 with W02, 7 and reduction of K2WO4-WO3 with elemental tung-sten. 8 Schaefer9 was first to prepare a defined rubidium tungsten bronze by reduction ofRb2COs-H2WO4 mix-tures with methane and hydrogen. The potassium bronzes, KVWO3, have been found to be tetragonal in the range8· 10 0.40< x< 0.57, with a= 12.285 Á. and