论文部分内容阅读
采用传统的高温固相烧结法制备了多晶样品(La1-xGdx)4/3Sr5/3Mn2O7(x=0,0.05),利用XRD检测了两样品的结构,结果表明:两样品均为Sr3Ti2O7型四方结构,空间群为I4/mmm,通过物性测量系统(PPMS)和超导量子磁强计(SQUID)测量了样品的磁性(M-T)以及电性(ρ-T),结果发现:两样品在低温区存在长程的铁磁态;当Gd掺入后,由于引起了结构的畸变,削弱了双交换作用,致使样品(La1-xGdx)4/3Sr5/3Mn2O7(x=0.05)的三维(3D)磁有序转变温度T3DC、磁化强度均降低。此外,样品在发生金属—绝缘体转变的同时伴随有铁磁—顺磁的转变。
The polycrystalline samples (La1-xGdx) 4 / 3Sr5 / 3Mn2O7 (x = 0,0.05) were prepared by the conventional high-temperature solid-state sintering method. The structures of the two samples were examined by XRD. The results showed that both samples were Sr3Ti2O7-type (MT) and electrical properties (ρ-T) of the samples were measured by physical property measurement system (PPMS) and superconducting quantum magnetometer (SQUID). The results showed that the two samples were stable at low temperature (Gdx) 4 / 3Sr5 / 3Mn2O7 (x = 0.05), the three-dimensional (3D) magnetic properties of the samples are impaired due to the structure distortion caused by Gd doping. Order transition temperature T3DC, magnetization decreased. In addition, the sample is accompanied by a ferromagnet-paramagnetic transition while it undergoes a metal-insulator transition.