Uniaxial-Pressure-Induced Release of Magnetic Frustration in a Triangular Lattice Antiferromagnet YbCuGe

Abstract

We have studied the effect of geometrical frustration on the antiferromagnetic order in the Yb-based triangular lattice compound YbCuGe below TN = 4.2 K by the measurements of magnetization and specific heat under hydrostatic and uniaxial pressures. By applying hydrostatic pressure P up to 1.34 GPa, TN hardly changes. By contrast, TN increases as P is applied along the hexagonal a axis, while TN decreases by the application of P along the c axis. The increase of TN only for P‖a suggests the release of the frustration inherent in the triangular lattice of Yb ions of this compound.

Influence of Anomalous Changes in the Crystal Structure on the Transport Properties of YbNi1−xCuxAl Series of Alloys

“…As a fine example, divalent Yb (nonmagnetic metal) under a pressure of 86 GPa becomes a superconductor before a stable trivalent (magnetic) state is reached, suggesting that magnetic instabilities may play a role in the appearance of superconductivity [ 4 ]. Another example is the antiferromagnetic YbCuGe, where the application of pressure induces a magnetic frustration in the triangular lattice of Yb ions of this compound [ 5 ]. On the other hand, the study of chemical substitution effects on the α-YbAlB 4 system by Mn substitution at the Al site influences the intermediate valence state with the appearance of an antiferromagnetic transition at 20 K, a relatively high value for Yb compounds [ 6 ].…”