Importance of In-Plane Anisotropy in the Quasi Two-Dimensional Antiferromagnet BaNi${}_2$V${}_2$O${}_8$

Abstract

The phase diagram of the quasi two-dimensional antiferromagnet BaNi${}_2$V${}_2$O${}_8$ is studied by specific heat, thermal expansion, magnetostriction, and magnetization for magnetic fields applied perpendicular to $\mathbf{c}$. At ${\mu }_0{H}^{\ast }\simeq 1.5$ T, a crossover to a high-field state, where $T_N(H)$ increases linearly, arises from a competition of intrinsic and field-induced in-plane anisotropies. The pressure dependences of $T_N$ and $H^{\ast }$ are interpreted using the picture of a pressure-induced in-plane anisotropy. Even at zero field and ambient pressure, in-plane anisotropy cannot be neglected, which implies deviations from pure Berezinskii-Kosterlitz-Thouless behavior.

4 pages, 4 figures

References in corpus (1)

• Quantum Monte Carlo study of S=1/2 weakly-anisotropic antiferromagnets on the square lattice

Cited by in corpus (2)

• Ferromagnetism and Lattice Distortions in the Perovskite YTiO${}_3$
• Heat Capacity and Magnetic Phase Diagram of the Low-Dimensional Antiferromagnet Y${}_2$BaCuO${}_5$