La0.4Ca0.6Mn0.98Ru0.02O3中的电致电阻效应研究

单相多晶锰氧化物样品La_0.4Ca_0.6Mn_0.98Ru_0.02O₃具有典型的电子相分离基态, 即低温下铁磁金属相与电荷有序绝缘相共存并竞争, 这为我们研究电致电阻效应提供了很好的模型。本论文基于此目的, 采用固相合成法制备了La_0.4Ca_0.6Mn_0.98Ru_0.02O₃的多晶陶瓷样品, 用X射线衍射证明了样品是单相, 并详细测量了样品的电致电阻效应。实验结果表明, 该体系的电阻率能够在大范围内被输入电流调控, 获得的电致电阻效应高达80%以上。此外, 低温下该样品的电阻态可以通过改变电流输入强度进行连续转换, 反映了样品基态在电流的激发下发生了改变。通过讨论, 我们认为这些观测到的物理效应起源于输入电流提升了样品中的铁磁金属相的稳定性。

Electroresistance in Phase Separated La0.4Ca0.6Mn0.98Ru0.02O3

Single-phase manganite La_0.4Ca_0.6Mn_0.98Ru_0.02O₃ shows a typical electronic phase separated state, i.e. the ferromagnetic metal and charge-ordered insulating phase. This provides an ideal platform for investigating electroresistance effect. The sample was synthesized by using standard solid state reaction method, and the pure phase was demonstrated using X-ray diffraction. The colossal electroresistance were measured at various input current intensities. The experiments reveal remarkable electroresistance effect (~80%) which can be triggered by increasing the current intensity. In addition, the resistance state of the sample can be switched immediately and repeatedly by switching the current intensity. The current stabilized ferromagnetic phase would be responsible for these phenomena.