Abstract

Crystal structure, temperature and field dependences of magnetization, high-field susceptibility, and magnetocaloric effect (MCE) of Ho_1 – xY_x(Co_0.84Fe_0.16)₂ polycrystalline compounds (x = 0–1) in magnetic fields up to 90 kOe in a temperature range of 5–400 K are investigated. An analysis of temperature dependences of magnetization (σ) showed that, depending on the yttrium content (x), up to three “critical” temperatures can be simultaneously present in the studied samples: spin-reorientation (T_sr), magnetic compensation point (T_comp), and Curie temperature (T_C). The temperature dependence of the high-field susceptibility (χ_hf) of all samples with x < 1 has an extremum in the vicinity of 100 K, where a significant MCE is observed, associated with a sharp change in the magnetization of the rare-earth sublattice. The temperature dependences of the magnetic entropy change (ΔS_m) and the adiabatic temperature change (ΔT_ad) have a complex shape and reflect all the above-mentioned “critical” temperatures observed at different x.

中文翻译：

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Ho1 – xYx(Co0.84Fe0.16)2 化合物的磁性和磁热性质

摘要

_{Ho 1 –  x} Y _x (Co _0.84 Fe _0.16 ) ₂多晶化合物 ( x = 0–1) 在高达 90 的磁场中的晶体结构、温度和磁场依赖性、高场磁化率和磁热效应 (MCE)研究了 5–400 K 温度范围内的 kOe。对磁化强度 (σ) 的温度依赖性的分析表明，根据钇含量 ( x )，研究样品中最多可以同时存在三个“临界”温度：自旋重定向 ( _Tsr )、磁补偿点 ( T _comp ) 和居里温度 (TC ₎。x < 1的所有样品的高场磁化率 (χ _hf ) 的温度依赖性在 100 K 附近有一个极值，其中观察到显着的 MCE，与稀土磁化的急剧变化有关亚晶格。磁熵变 (Δ S _m ) 和绝热温度变化 (Δ T _{ad ) 的温度依赖性具有复杂的形状，反映了在不同}x下观察到的所有上述“临界”温度。