Phase diagram of the Dzyaloshinskii-Moriya helimagnet Ba2CuGe2O7 in canted magnetic fields

Article

关键词: SPIN-WAVES;    WEAK FERROMAGNETISM;    TRANSITION;   

DOI  :  10.1103/PhysRevB.86.024417

来源: SCIE

【 摘 要 】

The evolution of different magnetic structures of noncentrosymmetric Ba2CuGe2O7 is systematically studied as a function of the orientation of the magnetic field H. Neutron diffraction in combination with measurements of magnetization and specific heat show a virtually identical behavior of the phase diagram of Ba2CuGe2O7 for H confined in both the (1,0,0) and (1,1,0) plane. The existence of a recently proposed incommensurate double-k AF-cone phase is confirmed in a narrow range for H close to the tetragonal c axis. For large angles enclosed by H and the c axis, a complexly distorted nonsinusoidal magnetic structure has recently been observed. We show that its critical field H-c systematically increases for larger canting. Measurements of magnetic susceptibility and specific heat finally indicate the existence of an incommensurate/commensurate transition for H approximate to 9T applied in the basal (a, b) plane and agree with a nonplanar, distorted cycloidal magnetic structure.

【 授权许可】

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