Metamagnetism

About: Metamagnetism is a research topic. Over the lifetime, 2023 publications have been published within this topic receiving 38108 citations.

Magnetic-field induced transition to the 1/2 magnetization plateau state in the geometrically frustrated magnet CdCr2O4.

Abstract: The magnetization of the geometrically frustrated spinel $\mathrm{C}\mathrm{d}{\mathrm{C}\mathrm{r}}_{2}{\mathrm{O}}_{4}$ was measured in pulsed fields of up to 47 T. We found a metamagnetic transition to a very wide magnetization plateau state with one half of the full moment of $S=3/2$ ${\mathrm{C}\mathrm{r}}^{3+}$ at 28 T, independent of the field direction. This is the first observation of magnetization plateau state realized in Heisenberg pyrochlore magnet. The plateau state can be ascribed to a collinear spin configuration with three-up and one-down spins out of four spins of each Cr tetrahedron. A large magnetostriction is observed at the transition in spite of the negligible spin-orbit couplings. We argue that spin frustration plays a vital role in this large spin-lattice coupling.

Density of states and magnetic properties of the rare-earth compounds RFe2, RCO2 and RNi2

Abstract: The density of states of yttrium compounds YM2 (M = Fe, Co, Ni) is calculated within a tight-binding scheme. Using the Stoner model, conclusions are drawn about their magnetic and electronic properties. In YCo2, we show that one has to introduce paramagnon effects in order to explain the electronic properties. The additional d-f interaction introduced by rare-earth atoms (R) in RM2 is treated with a Hartree-Fock approximation. Little change is obtained in iron and nickel compounds. Conversely, in RCo 2 compounds, the exchange field due to the rare-earth atoms can produce collective metamagnetism as described by Wohlfarth and Rhodes [1] and cobalt becomes magnetic. This effect stems from the position of the Fermi level of these compounds in a steep decrease of the density of states. Curie temperature, order of the transition and effect of an external magnetic field are studied following this method. Other consequences are drawn from the model.

Giant isotropic magnetostriction of itinerant-electron metamagnetic La(Fe0.88Si0.12)13Hy compounds

Abstract: La(FexSi1−x)13 compounds exhibit an itinerant-electron metamagnetic (IEM) transition above Curie temperature TC. The IEM transition in the compound with x=0.88 is accompanied by a giant volume change. From a practical viewpoint, TC was controlled by hydrogen absorption in order to obtain such a giant volume magnetostriction at room temperature. For the La(Fe0.88Si0.12)13H1.0 compound, the IEM transition occurs above TC=278 K, and a significant isotropic linear magnetostriction of about 0.3% at 7 T is induced in the vicinity of room temperature. This large magnetostriction is attributed to the giant volume magnetostriction of about 1% by the IEM transition.

Magnetic Properties of Cr1/3NbS2

Abstract: An intercalated 2H-type layer compound, Cr 1/3 NbS 2 , was investigated by magnetic and neutron diffraction measurements. It was found that this compound is a helimagnet with a very long period along the c -axis and with the spins in the c -plane. The magnetic behavior is similar to that of an easy-plane type ferromagnet except for the magnetization curve in the c -plane. The Curie temperature is 127 K. The saturation magnetization corresponds to 2.9 µ B /Cr. The uniaxial anisotropy constant, K 1 , is -1.46×10 6 ergs/cc at 4.2 K. The magnetizatiom curve in the c -plane shows a metamagnetic behavior, the critical field of which is as low as 1.5 kOe except near T c . Small angle scattering measurements showed a helical structure with Q =0.013 A -1 (480 A period). The helical spin structure and the metamagnetism is explained as due to the antisymmetric exchange interaction.