Experimental studies of novel magnetic refrigerants by high field X-ray diffraction measurements

高场X射线衍射测量新型磁性制冷剂的实验研究

• 批准号: 17560610
• 负责人: KOYAMA Keiichi
• 金额: $ 2.12万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17560610/
• 关键词: high magnetic field; powder X-ray diffraction; crystal structure; magnetic refrigerant; lst-order phase transition; magnetocaloric effect; structural transformation; 高磁気熱量材料; 包晶反応; スピン再配列; X線回折装置; 磁気体積効果; 磁気冷凍; 低温; 高磁気熱材料; 高磁歪材料; 磁場誘起形状記憶強

In this work, I have studied novel magnetic refrigerants by high X-ray diffraction measurements. I have clarified some topics as follows:1. I observed a field-induced magnetic and structural transition on large magnetocaloric material MnFeP_0.5As_0.5. The material has a hexagonal structure and shows that the parameters a and c deform by 0.5% and 1.0%, respectively, by magnetic field.2. Large magnetocaloric material Gd_5(GeFe)Si_2 shows a structural transformation from a monoclinic structure to an orthorhombic structure by high magnetic field.3. I observed a field-induced reverse martensitic transformation from an orthorhombic structure to a cubic structure in large magnetocaloric material Ni_<50>Mn_<36>Sn_<14>.4. The ferromagnetic shape memory alloy Ni_<50>Mn_<36>Sn_<14> shows a large magnetoresistance effect accompanied by the field-induced reverse martensitic transformation.5. I revealed the magnetic and thermoelectric properties of magnetic shape memory alloy Ni_<50>Mn_<36>Sn_<14> in high magnetic fields.6. I observed a metamagnetic (1st-order) transition of MnBi at high temperature of 630 K by high magnetic fields.7. MnBi shows a large magnetocaloric effect at the 1st-order magnetic transition temperature. By applying high magnetic field, the 1st-order magnetic transition temperature of MnBi increases at the rate of 2 KT^<-1>.8. Magnetic field and pressure induced magnetic transitions were observed in DyB_2C_2 below 10 K.

在这项工作中，我通过高 X 射线衍射测量研究了新型磁性制冷剂。我澄清了一些主题如下： 1．我在大型磁热材料 MnFeP_0.5As_0.5 上观察到场感应磁性和结构转变。该材料具有六方结构，磁场作用下参数a和c分别变形0.5%和1.0%。 2．大磁热材料Gd_5(GeFe)Si_2在强磁场作用下表现出从单斜结构到斜方结构的结构转变。 3．我在大型磁热材料 Ni_<50>Mn_<36>Sn_<14>.4 中观察到场致逆马氏体从斜方结构到立方结构的转变。铁磁形状记忆合金Ni_<50>Mn_<36>Sn_<14>表现出大的磁阻效应并伴有场致逆马氏体相变。 5．揭示了磁性形状记忆合金Ni_<50>Mn_<36>Sn_<14>在强磁场下的磁性能和热电性能。 6．我在630 K 的高温下通过高磁场观察到了MnBi 的变磁（一阶）转变。7． MnBi在一阶磁转变温度下表现出很大的磁热效应。通过施加强磁场，MnBi的一阶磁转变温度以2KT^<-1>.8的速率增加。在低于 10 K 的 DyB_2C_2 中观察到磁场和压力引起的磁转变。

项目成果

Magnetic properties of Ce(Fe_<1-x>Co_x)_2 under high pressure

Ce(Fe_<1-x>Co_x)_2高压下的磁性能

• 发表时间: 2005
• 期刊: J. Alloys and Compounds 408-412408-412
• 作者: Matsumoto;T.;Yanagida;M.;H.Okada
• 通讯作者: H.Okada

DyB_2C_2の強磁場高圧下における磁化測定

DyB_2C_2在强磁场和高压下的磁化测量

• 发表时间: 2007
• 作者: A.Konno;G.R.A.Kumara;S.Kaneko;B.Onwona-Agyeman;K.Tennakone;小山佳一
• 通讯作者: 小山佳一

Observation of reverse Martensitic transformation of ferromagnetic shape memory alloy Ni46Mn41In13 by high field X-ray diffraction experiments

高场X射线衍射实验观察铁磁形状记忆合金Ni46Mn41In13的逆马氏体相变

• 发表时间: 2007
• 作者: K. Koyama;H. Okada;K. Watanabe;. Y. Yasuda;T. Kanomata;R. Kainuma;W. Ito;K. Oikawa;K. Ishida.
• 通讯作者: K. Ishida.

Magnetization measurements of DyB_2C_2 under high pressure and high magnetic fields

DyB_2C_2在高压高磁场下的磁化测量

• 发表时间: 2007
• 期刊: Physica B 403
• 作者: R.A.Wach;M.Sugimoto;A.Idesaki;M.Yoshikawa;O. Tegus;K. Koyama;小野木哲也;K. Koyama;K. Koyama;K. Koyama
• 通讯作者: K. Koyama

Development of high field and high temperature X-ray diffraction apparatus

高场高温X射线衍射仪的研制

• 发表时间: 2002
• 作者: Y. Mitsui;K. Koyama;and K. Watanabe
• 通讯作者: and K. Watanabe