Abstract Studies on the Mn-substitution induced modification in the structural, thermal, magnetic and magnetocaloric properties of TbCrO3 orthochromite are presented. The phase formation and purity of the samples were examined by analyzing X-ray diffraction (XRD) patterns. Magnetization measurements as a function of temperature reveal the antiferromagnetic ordering of Cr3+ spins (TN1) at ∼ 157 K and Tb3+ spins (TN2) ∼ 5 K for TbCrO3 sample. The substitution of Mn-atoms at Cr-site results in a decrease in TN1 whereas an increase in TN2. The isothermal magnetization measurements reveal the presence of metamagnetic transition at 5 K and 2 K. Results of, ac and dc magnetization and isothermal remnant magnetization suggest a spin-glass like ordering below TN2. The heat capacity measurements show peaks corresponding to the magnetic ordering of Cr3+ and Tb3+ spins. The temperature variation of magnetic entropy change (-ΔSm) for different ΔH suggests the presence of the magnetocaloric effect in the vicinity of TN2. It is found that values of -ΔSm decreases with the increase in Mn-substitution. Present results have been understood in terms of modifications in magnetic exchange interactions introduced by the Mn-substitution at Cr-site.

中文翻译：

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Mn取代对TbCrO 3 磁热性能的影响

摘要 介绍了锰取代诱导改性 TbCrO3 正铬铁矿的结构、热、磁和磁热性能的研究。通过分析 X 射线衍射 (XRD) 图案来检查样品的相形成和纯度。作为温度函数的磁化测量显示，对于 TbCrO3 样品，Cr3+ 自旋 (TN1) 在 ~ 157 K 和 Tb3+ 自旋 (TN2) ~ 5 K 处的反铁磁排序。Cr 位Mn 原子的取代导致TN1 减少而TN2 增加。等温磁化测量揭示了在 5 K 和 2 K 处存在变磁转变。交流和直流磁化以及等温残余磁化的结果表明，TN2 以下的自旋玻璃状排序。热容量测量显示对应于 Cr3+ 和 Tb3+ 自旋的磁序的峰值。不同 ΔH 的磁熵变 (-ΔSm) 的温度变化表明 TN2 附近存在磁热效应。发现-ΔSm 的值随着Mn 取代度的增加而降低。目前的结果已经通过 Cr 位的 Mn 取代引入的磁交换相互作用的修改来理解。