School of Chemistry and Materials Science of Shanxi Normal University & Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education, Linfen 041004, China.
Nanoscale. 2018 Jun 14;10(23):11028-11033. doi: 10.1039/c8nr02272k.
Ferromagnetic Cr2Te3 nanorods were synthesized by a one-pot high-temperature organic-solution-phase method. The crystalline phases and magnetic properties can be systematically tuned by varying the molar ratio of the Cr and Te precursors. A magnetically hard phase, identified as chemically ordered Cr2Te3, is the dominating one at the precursor ratio between Cr : Te = 1 : 1.2 and 1 : 1.8. A magnetically soft phase, attributed to chemical disorder due to composition inhomogeneity and stacking faults, is present under either Cr-rich or Te-rich synthesis conditions. A large coercivity of 9.6 kOe is obtained for a Cr : Te precursor ratio of 1 : 1.8, which is attributed to the large magnetocrystalline anisotropy of ordered Cr2Te3 nanorods, and verified by density-functional theory calculations. The hard and soft phases sharing coherent interfaces co-exist in a seemingly single-crystalline nanorod, showing an unusual transition from exchange-coupled behavior at higher temperatures to two-phase behavior as the temperature is lowered.
通过一锅高温有机溶液法合成了铁磁 Cr2Te3 纳米棒。通过改变 Cr 和 Te 前体的摩尔比，可以系统地调节晶体相和磁性能。在 Cr:Te=1:1.2 和 1:1.8 的前体比下，主要存在化学有序的 Cr2Te3 硬磁相。在富 Cr 或富 Te 的合成条件下，存在归因于成分不均匀和堆垛层错导致的化学无序的软磁相。当 Cr:Te 前体比为 1:1.8 时，获得了 9.6 kOe 的大矫顽力，这归因于有序 Cr2Te3 纳米棒的大磁晶各向异性，并通过密度泛函理论计算得到了验证。硬磁相和软磁相在看似单晶纳米棒中共存，表现出从高温下的交换耦合行为到低温下的两相行为的不寻常转变。
