Giant volume magnetostriction in the Y 2

An investigation of the Y2Fe17 compound belonging to the class of intermetallic alloys of rare-earth and 3d-transition metals is presented. The magnetization, magnetostriction, and thermal expansion of the Y2Fe17 single crystal were studied. The forced magnetostriction and magnetostriction constants were investigated in the temperature range of the magnetic ordering close to the room temperature. The giant field induced volume magnetostriction was discovered in the room temperature region in the magnetic field up to 1.2 T. The contributions of both anisotropic single-ion and isotropic pair exchange interactions to the volume magnetostriction and magnetostriction constants were determined. The experimental results were interpreted within the framework of the Standard Theory of Magnetostriction and the Landau thermodynamic theory. It was found out that the giant values of the volume magnetostriction were caused by the strong dependence of the 3d-electron Coulomb charge repulsion on the deformations and width of the 3d-electron energy band

Magnetocrystalline Anisotropy of Tb1.1\text{}_{1.1}(FeCo)11\text{}_{11}Ti

The Tb$\text{}_{1.1}$Fe$\text{}_{11-x}$Co$\text{}_{x}$Ti (x = 0, 1, 2, 3, 4) compounds with the ThMn$\text{}_{12}$-type structure were studied by using the torque and magnetization measurements in order to investigate temperature and composition behavior of the magnetocrystalline anisotropy. The Tb$\text{}_{1.1}$(FeCo)$\text{}_{11}$Ti single crystals demonstrated spin reorientation transition from easy axis to easy plane with the decrease in temperature. The substitution of Co for Fe produces an enhancement of the Curie temperatures, decreases temperatures of spin reorientation transition and appearance of canted structure

Adiabatic temperature change of micro- and nanocrystalline Y2Fe17 heat-exchangers for magnetic cooling

Magnetic refrigerants are used as heat exchangers to provide rapid heat transfer between magnetocaloric materials and heat-transfer liquid. An important question is how to turn bulk magnetocaloric materials into porous structures with superior heat transfer properties and cooling performance. We discuss two methods for assembling Y2Fe17 rapidly quenched ribbons into heat exchangers of desired geometry stacked 100 mm thick plates with 100 mm gaps: the first method consists in gluing rapidly quenched ribbons using thermoconductive epoxy; the second is sintering stacked ribbons at a temperature of 30 K below the melting point of the Y2Fe17 phase. These approaches are promising with regards to making near-net shaped magnetic refrigerants. We report on adiabatic temperature change Delta T-ad, magnetic entropy change Delta S-m and thermal conductivity lambda of rapidly quenched Y2Fe17 ribbons, obtained at different quenching rates. A direct correlation between the lattice parameters of the Y2Fe17, Delta T-ad and Delta S-m in rapidly quenched samples is observed. (C) 2016 Elsevier B.V. All rights reserved

Giant volume magnetostriction in the Y2Fe17 single crystal at room temperature

Under the terms of the Creative Commons Attribution 3.0 Unported License.An investigation of the Y2Fe17 compound belonging to the class of intermetallic alloys of rareearth and 3d-transition metals is presented. The magnetization, magnetostriction, and thermal expansion of the Y2Fe17 single crystal were studied. The forced magnetostriction and magnetostriction constants were investigated in the temperature range of the magnetic ordering close to the room temperature. The giant field induced volume magnetostriction was discovered in the room temperature region in the magnetic field up to 1.2 T. The contributions of both anisotropic singleion and isotropic pair exchange interactions to the volume magnetostriction and magnetostriction constants were determined. The experimental results were interpreted within the framework of the Standard Theory of Magnetostriction and the Landau thermodynamic theory. It was found out that the giant values of the volume magnetostriction were caused by the strong dependence of the 3delectron Coulomb charge repulsion on the deformations and width of the 3d-electron energy band.The work was supported by RFBR Grant Nos. 13-02-00916 and 12-02-31516.Peer reviewe