掺杂蓝青铜的Peierls相变及非线性电输运性质  

Peierls Phase Transition and Nonlinear Transport Study of Doped Blue Bronzes

作　　者：王定理[1] 肖清明[1] 汤五丰[1] 赵同云[1] 石兢[1] 田德诚[1] 

机构地区：[1]武汉大学物理学系,武汉430072

出　　处：《武汉大学学报（自然科学版）》1999年第3期335-338,共4页Journal of Wuhan University(Natural Science Edition)

基　　金：国家自然科学基金;国家教委基金

摘　　要：对钾钼蓝青铜 Ｋ０．３ Ｍｏ Ｏ３ 及其 Ｎａ 离子掺杂单晶 Ｋ０．３－ ｘ Ｎａｘ Ｍｏ Ｏ３ （ｘ ＝ ０．０２， ０．０５，０．１０）系列的 Ｐｅｉｅｒｌｓ 相变及７７ Ｋ 非线性电输运性质进行了系统研究发现 Ｎａ 离子掺杂对 Ｋ０．３ Ｍｏ Ｏ３ 单晶的 Ｐｅｉｅｒｌｓ 相变温度无明显改变，本文认为这是由于 Ｎａ 离子所起的两种相反作用的结果； Ｎａ 离子掺杂使样品的半导体能隙和第一阈值电场均明显增大，用钉扎理论对后者给予了定性解释；非线性电荷密度波电流 Ｉ Ｃ Ｄ Ｗ 与外场间满足指数关系： Ｉ Ｃ Ｄ Ｗ∝（ Ｖ／ Ｖ Ｔ － １）α，其中α≈３／２，并随 ＮａTemperature dependence of Ohmic resistance, and nonlinear current\|voltage ( I \| V ) characteristics at 77 K were systematically studied in pure potassium blue bronze K 0.3 MoO 3 and Na\|doped alloy bronzes K 0.3- x Na x MoO 3 ( x = 0.02, 0.05, 0.10). No considerable influence of Na ions doping in K 0.3 MoO 3 was found on the Peierls transition temperature, while obvious enhancement on semiconductor gap and remarkable influence on the first threshold field were observed. We attribute the first phenomenon to two opposite effects of Na ions. And the depinning model is proposed to account for the latter. The analytical form of nonlinear charge\|density wave current I CDW in a moderate field range fits the power\|law relation, i.e. I CDW ∝ ( V / V T-1) α, where the exponent α is about 3/2 and slightly enhanced by Na ions doping.

关 键 词：掺杂蓝青铜 PEIERLS相变 非线性电输运 蓝青铜 

分 类 号：TG146.11[一般工业技术—材料科学与工程] O738[金属学及工艺—金属材料]