Ultrahigh-Magnetic-Field Magnetization Of Multi-Kagome-Strip (Mks) Lattice Spin-Frustrated Magnet K2mn3(Oh)(2)(Vo4)(2)

The magnetic properties of K2Mn3(OH)(2)(VO4)(2) are investigated up to a very high magnetic field of over 200 T. In this material, Mn atoms form a two-dimensional multi-kagome-strip (MKS) lattice, which has the characteristics of both kagome and diamond-chain lattices. The Weiss temperature Theta (approximate to -347 K) indicates strong antiferromagnetic interactions, but the Neel temperature T-N (= 50 K) is much lower than the absolute value of Theta. This demonstrates the effect of geometric frustration and low dimensionality. The high-field magnetization curve, obtained by a Faraday rotation measurement up to 207 T, exhibits a narrow plateau at about 1/3 of the saturation magnetization. The slope of the magnetization curve is much steeper above the plateau than below the plateau. This behavior can be interpreted in terms of a spin-lattice coupling.