Successive Magnetic Transitions of Ca₂CoSi₂O₇in High Magnetic Fields

Abstract

Magnetic and dielectric properties of \\aa kermanite Ca$_2$CoSi$_2$O$_7$\nsingle crystals were investigated in pulsed high magnetic fields. In magnetic\nfields along the $c$ axis, this material shows a magnetization plateau in a\nwide range of field below the saturation. Magnetization processes for fields\nalong the $a$ and $b$ axes show multiple anomalies but different traces to each\nother, indicating the breaking of four-fold symmetry. Measurements of the\nmagnetoelectric effects exhibit the changes in electric polarization according\nto the changes in the spin system. The experimentally determined quadratic\nmagnetoelectric tensor is consistent with that expected in the crystal symmetry\nof orthorhombic $P2_12_12$.\n