Structural and magnetic properties of a new cubic spinel LiRhMnO4

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:481

Article

Kundu, S.¹  Dey, T.²  Prinz-Zwick, M.³  Buettgen, N.³  Mahajan, A., V¹ 

[1] Indian Inst Technol, Dept Phys, Mumbai 400076, Maharashtra, India

[2] Univ Augsburg, Ctr Elect Correlat & Magnetism, Expt Phys 6, D-86159 Augsburg, Germany

[3] Univ Augsburg, Ctr Elect Correlat & Magnetism, Expt Phys 5, D-86159 Augsburg, Germany

关键词: Geometric frustration;    Spinel;    Spin-glass;    Memory effect;    Aging effect;    NMR;   

DOI  :  10.1016/j.jmmm.2019.02.012

来源: Elsevier

【 摘 要 】

We report the structural and magnetic properties of a new system LiRhMnO4 (LRMO) through X-ray diffraction, bulk magnetization, heat capacity and Li-7 nuclear magnetic resonance (NMR) measurements. LRMO crystallizes in the cubic space group Fd (3) over barm. From the DC susceptibility data, we obtained the Curie-Weiss temperature theta(cw) = - 26 K and Curie constant C = 1.79 Kcm(3)/mol suggesting antiferromagnetic correlations among the magnetic Mn4+ ions with an effective spin S = 3/2. At H = 50 Oe, the field cooled and zero-field cooled magnetizations bifurcate at a freezing temperature, T-f = 4.45 K, which yields the frustration parameter f = vertical bar theta(CW)vertical bar/T-f > 5. AC susceptibility, shows a cusp-like peak at around T-f, with the peak position shifting as a function of the driving frequency, confirming a spin-glass-like transition in LRMO. LRMO also shows typical spin-glass characteristics such as memory effect, aging effect and relaxation. In the heat capacity, there is no sharp anomaly down to 2 K indicative of long-range ordering. The field sweep Li-7 NMR spectra show broadening with decreasing temperature without any spectral line shift. The Li-7 NMR spin-lattice and spin-spin relaxation rates also show anomalies due to spin freezing near T-f.

【 授权许可】

Free