Magnetic anisotropy and the phase diagram of chiral MnSb2O6
Magnetic anisotropy and the phase diagram of chiral MnSb2O6
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DOI：
10.1103/physrevb.94.104408
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发表时间：
2016-09
影响因子：
3.7
通讯作者：
J. Werner;C. Koo;R. Klingeler;A. Vasiliev;Y. Ovchenkov;A. Polovkova;G. Raganyan;E. Zvereva
中科院分区：
文献类型：
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作者：
J. Werner;C. Koo;R. Klingeler;A. Vasiliev;Y. Ovchenkov;A. Polovkova;G. Raganyan;E. Zvereva
本文报道了结构手性和磁手性MnSb_2O_6的磁相图和低能磁振子激发。比热和静态磁化强度分别在9和30 T的磁场中进行了研究，而动态磁特性则通过X波段以及可调谐高频电子自旋共振谱进行了探测。低于TN = 11.5 K，我们观察到反铁磁共振模式，这意味着小，但有限的平面各向异性显示在零场分裂的20 GHz。用各向异性场BA = 0.02T的易平面双子格模型对数据进行了很好的描述。交换场BE = 13 T是由脉冲场磁化导出的饱和场得到的。自旋结构的小的各向异性的一个关键作用是反映了竞争的反铁磁相出现，在T = 2 K，在小磁场在BC 1 $\约$0.5 T和BC 2 = 0.9 T。我们讨论的结果在自旋重取向和有利于螺旋自旋结构的摆线基态，在B = 0，是稳定的平面各向异性的小磁场。TN以上，短程磁相关高达>=60 K和磁熵的变化，以及TN以上反映了受挫的Mn 2+离子在MnSb 2 O 6的三角形排列。
The magnetic phase diagram and low-energy magnon excitations of structurally and magnetically chiral MnSb2O6 are reported. The specific heat and the static magnetization are investigated in magnetic fields up to 9 and 30 T, respectively, while the dynamicmagnetic properties are probed by X-band as well as tunable high-frequency electron spin-resonance spectroscopy. Below TN = 11.5 K, we observe antiferromagnetic resonance modes which imply small but finite planar anisotropy showing up in a zero-field splitting of 20 GHz. The data are well described by means of an easy-plane two-sublattice model with the anisotropy field BA = 0.02 T. The exchange field BE = 13 T is obtained from the saturation field derived from the pulsed-field magnetization. A crucial role of the small anisotropy for the spin structure is reflected by competing antiferromagnetic phases appearing, at T = 2 K, in small magnetic fields at BC1 $\approx$ 0.5 T and BC2 = 0.9 T. We discuss the results in terms of spin reorientation and of small magnetic fields favoring helical spin structure over the cycloidal ground state which, at B = 0, is stabilized by the planar anisotropy. Above TN, short-range magnetic correlations up to >=60 K and magnetic entropy changes well above TN reflect the frustrated triangular arrangement of Mn2+ ions in MnSb2O6.