La <sub> 1-x </ Sub> Sr <sub> The X </ Sub> Of Mno <sub> 3 </ Sub> System Structure And Light-induced Polarization Transport Properties

Doped manganese oxides, Lai1-xSrxMnO3 (LSMO), with distorted perovskite structures was prepared by traditional solid reaction method. Thin films with thickness of 50 nm were prepared by a single-target magnetron sputtering method on LaAlO3 substrate. It is shown that with increasing doped value x, structures of the crystals change its low symmetry into high symmetry and doping with praseodymium can induce larger crystal structure distortion than other elements.It is found that the systematic peak resistance temperature (Tp) increased with the doped value x, as La1-xSrxMnO3 films' resistance-temperature property is studied. A La0.5Sr0.5MnO3 film with Tp=420K was obtained, and it has not been reported until now as we know. It is revealed that the system is metal behavior under low temperature zone (T<Tp) . The systematic transport property is obviously changed by optical and magnetic fields. And it is thought to be the outer fields which have influence on the systematic spin system.Finally, some preliminary experiments on researching CMR effect and phase transition by optical method were carried out.