Heat Capacity and Magnetic Phase Diagram of the Low-Dimensional Antiferromagnet Y2BaCuO5
نویسندگان
چکیده
A study by specific heat of a polycrystalline sample of the low-dimensional magnetic system Y2BaCuO5 is presented. Magnetic fields up to 14 T are applied and permit to extract the (T ,H) phase diagram. Below μ0H ∗ ≃ 2 T, the Néel temperature, associated with a three-dimensional antiferromagnetic long-range ordering, is constant and equals TN = 15.6 K. Above H ∗, TN increases linearly with H and a field-induced increase of the entropy at TN is related to the presence of an isosbestic point at TX ≃ 20 K, where all the specific heat curves cross. A comparison is made between Y2BaCuO5 and the quasi-two-dimensional magnetic systems BaNi2V2O8, Sr2CuO2Cl2, and Pr2CuO4, for which very similar phase diagrams have been reported. An effective field-induced magnetic anisotropy is proposed to explain these phase diagrams.
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