Heat Capacity and Magnetic Phase Diagram of the Low-Dimensional Antiferromagnet Y${}_2$BaCuO${}_5$

Abstract

A study by specific heat of a polycrystalline sample of the low-dimensional magnetic system Y${}_2$BaCuO${}_5$ is presented. Magnetic fields up to 14 T are applied and permit to extract the ($T$,$H$) phase diagram. Below ${\mu }_0{H}^{\ast }\simeq 2$ T, the Néel temperature, associated with a three-dimensional antiferromagnetic long-range ordering, is constant and equals $T_N=15.6$ K. Above $H^{\ast }$, $T_N$ increases linearly with $H$ and a field-induced increase of the entropy at $T_N$ is related to the presence of an isosbestic point at $T_X\simeq 20$ K, where all the specific heat curves cross. A comparison is made between Y${}_2$BaCuO${}_5$ and the quasi-two-dimensional magnetic systems BaNi${}_2$V${}_2$O${}_8$, Sr${}_2$CuO${}_2$Cl${}_2$, and Pr${}_2$CuO${}_4$, for which very similar phase diagrams have been reported. An effective field-induced magnetic anisotropy is proposed to explain these phase diagrams.

14 pages, 7 figures

References in corpus (2)

• Quantum Monte Carlo study of S=1/2 weakly-anisotropic antiferromagnets on the square lattice
• Importance of In-Plane Anisotropy in the Quasi Two-Dimensional Antiferromagnet BaNi${}_2$V${}_2$O${}_8$

Cited by in corpus (1)

• Ferromagnetism and Lattice Distortions in the Perovskite YTiO${}_3$