论文标题
磁性稀释在铁磁柱中的异常效果，排序$ \ mathrm {sm_2mnmnmn_ {4-x} ti_xo_ {12}}} $ perovskites $ perovskites
Unusual effects of magnetic dilution in the ferrimagnetic columnar ordered $\mathrm{Sm_2MnMnMn_{4-x}Ti_xO_{12}}$ perovskites
论文作者
论文摘要
已经采用了粉末中子衍射实验来确定位点选择性磁稀释液在SM2MNMNMN4-X TIX O12 O12 A位置柱柱上订购四倍的perovskite锰矿（x = 1，x = 2和x = 3）。我们表明，在所有三个组合物中，Mn离子分别采用了27 K，62 K和34 K以下的共线铁磁结构。在x = 1和x = 2样品之间观察到排序温度的意外升高，这表明与平均场行为有很大的不同。通过大量减少整个系列中观察到的理论基态磁矩，这表明存在自旋波动和 / /或无序，这一结果得到了证实。我们表明，X = 3样品中的长距离磁顺序发生在B-B交换的渗透阈值以下，只有在SM2MNMNMN4-XTIXO12中的磁顺序通过A-B和B-B交易所介导的磁顺序才能理解，因此可以通过A-B B和B-B交换介导，因此确认了A-B交换相互作用在这些材料中的重要性。最后，我们表明位点选择性磁稀释可以调整铁磁补偿点，并引入温度引起的磁化逆转。
Powder neutron diffraction experiments have been employed to establish the effects of site-selective magnetic dilution in the Sm2MnMnMn4-x Tix O12 A-site columnar ordered quadruple perovskite manganites (x = 1, x = 2 and x = 3). We show that in all three compositions the Mn ions adopt a collinear ferrimagnetic structure below 27 K, 62 K and 34 K, respectively. An unexpected increase in the ordering temperature was observed between the x = 1 and x = 2 samples, which indicates a considerable departure from mean field behaviour. This result is corroborated by large reductions in the theoretical ground state magnetic moments observed across the series, which indicate the presence of spin fluctuations and or disorder. We show that long range magnetic order in the x = 3 sample, which occurs below the percolation threshold for B-B exchange, can only be understood to arise if magnetic order in Sm2MnMnMn4-xTixO12 is mediated via both A-B and B-B exchange, hence confirming the importance of A-B exchange interactions in these materials. Finally we show that site-selective magnetic dilution enables the tuning of a ferrimagnetic compensation point and the introduction of temperature-induced magnetization reversal.
