A series of Gd_1−xHo_xMnO₃ (x = 0, 0.1 and 0.2) compounds known to exhibit multiferroic properties has been investigated for their structural, magnetic and magnetocaloric properties. X-ray diffraction analysis confirms the presence of single orthorhombic phase at room temperature in all the compositions. Low temperature magnetocaloric properties of these compounds have been studied through specific heat measurements in the temperature range of 0–80 K under different magnetic fields of 0, 2 and 5 T. These studies also revealed the existence of Mn³⁺ ordering transition and lock-in transition (T_lock) near 40 K and 20 K, respectively. These compounds displayed antiferromagnetic (AFM) ordering of Gd³⁺ ions at low temperatures below 10 K. The magnetocaloric effect has been quantified in terms of the magnetic entropy change (ΔS)_M and adiabatic temperature change (ΔT)_ad in the vicinity of AFM transitions.

中文翻译：

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Gd 1-x Ho x MnO 3多铁化合物的磁热性质

研究了一系列 已知具有多铁性的Gd _{1- x} Ho _x MnO ₃（x = 0、0.1和0.2）化合物的结构，磁性和磁热特性。X射线衍射分析证实了在所有组合物中在室温下存在单个正交相。通过在0、2和5 T的不同磁场下在0–80 K的温度范围内的比热测量，研究了这些化合物的低温磁热性质。这些研究还揭示了Mn ³⁺有序转变和锁相的存在。过渡中（T_锁）分别接近40 K和20K。这些化合物显示的Gd的反铁磁（AFM）排序³⁺离子在低于10 K的磁热效应在磁熵变的形式进行了量化低温（Δ小号）_中号和绝热温度变化（Δ Ť）_广告附近AFM过渡。