锰位掺杂La0.7Ba0.3Mn0.95X0.05O3(X=Mn, Cr, Fe, Co)薄膜光诱导特性研究

Photoinduced Characteristics of Mn Site Doped La0.7Ba0.3Mn0.95X0.05O3 (X=Mn, Cr, Fe, Co) Thin Films

摘要:

用固相反应法制备La0.7Ba0.3Mn0.95X0.05O3(X=Mn，Cr，Fe，Co)系列块材，并利用磁控溅射法在LaAlO3单晶衬底上制备薄膜，研究过渡金属元素（Cr，Fe和Co）锰位掺杂对La0.7Ba0.3MnO3（LBMO）薄膜光诱导特性的影响。研究表明，Cr，Fe和Co掺杂均导致薄膜的金属-绝缘转变温度（TP）降低，电阻率和光致电阻率相对变化的最大值（LRmax）增大。其中Fe离子对体系影响最大，Co离子次之，Cr离子影响最小。激光诱导在不同温区对薄膜电阻率的影响不同，在低温（T< TP）区表现为光致电阻率增大，在高温区（T> TP）表现为光致电阻率减小。从过渡金属Cr，Fe和Co离子自身电子结构和晶格效应的角度出发，讨论了样品输运行为和光诱导特性的内在机理。

Abstract:

The compounds of La0.7Ba0.3Mn0.95X0.05O3 (X= Mn, Cr, Fe, Co) were prepared by a conventional solid reaction method and then their films were prepared on LaAlO3 single crystal substrate by a magnetron sputtering method. The effects of the Mn site doping of transition elements (Cr, Fe, Co) on the photoinduced properties of the La0.7Ba0.3MnO3 (LBMO) films were investigated. Results indicate that the transition element doping of Cr, Fe or Co causes a decrease of the insulator-metal transition temperature (Tp) and an increase of the maximum relative variation (LRmax) of resistivity and the photoinduced resistivity. Among them, Fe has the largest effect, Co comes second and Cr has the smallest. Laser induction has different influences on the resistivity of films in different temperature zones. In a low temperature zone (TTp) it is decreased. The intrinsic mechanism of the transport behavior and photoinduced properties was discussed in view of the electronic structure and lattice effect of Cr, Fe and Co.