摘 要：采用传统的溶胶凝胶法制备(La0.8Te0.2MnO2)0.7/(ZrO2)0.3(LTMO/ZrO2)多晶块体,研究发现样品从40K升温至320K过程中发生金属—绝缘相变，相变点温度TMI为210K，TMI处的磁电阻（MR）值为398.051。当T<TMI时，样品MR随着温度的升高而增大，即dR/dT>0；相反，当T>TMI，有dR/dT<0。理论研究表明，复合体系在高温区的输运方式为非绝热近似时的小极化子输运模式。当在块体LTMO/ZrO2外加一个垂直于电流方向的0.9T的磁场时，发现MR-T曲线是温度的双峰不对称曲线，TMI (210K)位于MR-T双峰所对应的温度Tp1（110K）和Tp2（270K）之间，且在TMI的两端分别出现了明显的庞磁阻效应（CMR）,表明在LTMO/ZrO2复合样品中存在两种导电通道：一个过LTMO相，另一通道与相有关。最后，我们还用高精度电阻表测量了块体LTMO/ZrO2在波长为532nm、输出功率40mW连续激光照射下的电阻率变化情况，结果表明在激光诱导下具有明显的与自旋相关的弛豫现象。
关键词：(La0.8Te0.2MnO2)0.7/(ZrO2)0.3块体，CMR，光诱导效应
Abstract： (La0.8Te0.2MnO2)0.7/(ZrO2)0.3 (LTMO/ZrO2) polycrystalline block was synthesized by traditional sol-gel method, and it was found that the sample from 40K to 320K warming occurred in the process of metal-insulators phase change. Change point temperature TIM was 210K, and TIM place of the magnetic resistance(MR) value was 398.051. When T<TMI, MR of samples increases with the rise of temperature, in other words, dR/dT>0. Instead, when T>TMI, dR/dT<0. Theory research indicates that the compound system in high transport for the adiabatic approximation way of extremely small anti-fuzzy transport mode. When plusing a perpendicular to the direction of the current 0.9 T magnetic field in the block LTMO/ZrO2, we found MR-T curve is temperature bimodal even than symmetric curve,and (210K) is located in MR-T twin peaks of the corresponding temperature Tp1(110K) and the Tp2(270K), and between TMI respectively in both ends of the there is an obvious ponti magnetic resistance effects(CMR), which show that in LTMO/ZrO2 composite samples there are two conductive path: one was LTMO phase, and another channel was related to the phase ZrO2. Finally, we also use high precision resistance meter to measure the block LTMO/ZrO2 in wavelength for 532 nm, output power 40 mW continuous laser irradiation of resistivity change. The results indicate that block in the laser induced has obvious and spin related relaxation phenomenon.
Key words：(La0.8Te0.2MnO2)0.7/(ZrO2)0.3 block；CMR effect；photo-induced effect；electron-doped
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