Preparation, crystal structure, heat capacity, magnetism, and the magnetocaloric effect of Pr5Ni1.9Si3 and PrNi
Preparation, crystal structure, heat capacity, magnetism, and the magnetocaloric effect of Pr5Ni1.9Si3 and PrNi
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DOI：
10.1103/physrevb.68.134452
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发表时间：
2003-10
影响因子：
3.7
通讯作者：
A. O. Pecharsky;Y. Mozharivskyj;K. Dennis;K. Gschneidner;R. Mccallum;G. Miller;V. Pecharsky
中科院分区：
文献类型：
--
作者：
A. O. Pecharsky;Y. Mozharivskyj;K. Dennis;K. Gschneidner;R. Mccallum;G. Miller;V. Pecharsky
单相Pr5Ni1。制备了9Si3和PrNi，并用差热分析、单晶和粉末X射线衍射法对其进行了表征。在5~400K的Pr5Ni1温度范围内，通过测量在100kOe以下的磁场中的热容和50kOe以下的磁化强度来研究它们的热学和磁性。9Si3在50K时磁性有序，在25K时经历第二次转变。从磁化强度和磁热效应(MCE)的行为推断，材料的磁性基态中既存在铁磁成分，也存在反铁磁性成分。PrNi的热容和磁热效应证实了它在19K时具有铁磁性。9Si3和PrNi表现出中等的磁热效应。Pr5Ni1的最大平均磁能级.9Si3为3.4K，当磁场从0变化到75kOe时，在50K下观察到它的存在。PrNi的最大平均磁能级为4.2K，当磁场从0到100kOe变化时，最大磁化能出现在19K。
Single-phase Pr 5 Ni 1 . 9 Si 3 and PrNi were prepared and characterized by using differential thermal analysis, single crystal, and powder x-ray diffraction. Their thermal and magnetic properties were studied by measuring heat capacity as a function of temperature in magnetic fields up to 100 kOe and magnetization as a function of magnetic field up to 50 kOe over the temperature range from 5 to 400 K. Pr 5 Ni 1 . 9 Si 3 orders magnetically at 50 K, and it undergoes a second transition at 25 K. As inferred from the behavior of the magnetization and magnetocaloric effect (MCE), both ferromagnetic and antiferromagnetic components are present in the magnetic ground state of the material. The heat capacity and magnetocaloric effect of PrNi confirm that it orders ferromagnetically at 19 K. Both Pr 5 Ni 1 . 9 Si 3 and PrNi exhibit moderate magnetocaloric effects. The maximum MCE for Pr 5 Ni 1 . 9 Si 3 is 3.4 K and it is observed at 50 K for a magnetic field change from 0 to 75 kOe. The maximum MCE for PrNi is 4.2 K. which occurs at 19 K for a magnetic field change from 0 to 100 kOe.