La_(0.5)Ca_(0.5)MnO_3内禀与界面电脉冲诱导电阻转变效应的比较

Comparison bwtween intrinsic and interfacial electrical pulse induced resistance effects in La_(0.5)Ca_(0.5)MnO_3 ceramics

一般地,钛矿结构锰氧化物的电脉冲诱导电阻转变(EPIR)效应源于非内禀界面处的肖特基势垒.本文采用固相烧结法制备了La0.5Ca0.5MnO3(LCMO)陶瓷样品,用四线测量模式对样品电输运性质,特别对其内禀EPIR效应和忆阻器行为进行了研究.室温下,尽管样品在四线测量模式下的I-V特性曲线呈欧姆线性规律,但在适当的脉冲电压刺激下,仍能诱导产生明显、稳定的EPIR效应.通过与二线模式的界面EPIR比较,发现LCMO内禀EPIR效应具有更小的脉冲临界电压、更好的稳定性和抗疲劳特性,是稀土掺杂锰氧化物中观察到的一类新颖的EPIR效应.

In general, the electrical pulse induced resistance （EPIR） effect of perovskite manganite originates from the interfacial Schottky barrier between the metal electrode and the surface of sample. In this work, La0.5Ca0.5MnO3 （LCMO） ceramic samples are synthe-sized by solid state reaction and the transport properties, especially the EPIR effect are investigated using 4-wire measurement mode. Although the I-V curve of LCMO shows ohmic linearity under the 4-wire measurement mode at room temperature, a stable and re-markable EPIR effect can still be observed when the pulse voltage is more than the critical value. Through the comparison between the intrinsic EPIR under 4-wire mode and the interface one under 2-wire mode, we find that the intrinsic EPIR of LCMO has a smaller critical pulse voltage to induce the effect, but it has a better anti-fatigue property. The intrinsic EPIR effect is a novel one which is observed in rare earth doped manganites.