Knafo W, Meingast C, Grube K, Drobnik S, Popovich P, Schweiss P, Adelmann P, Wolf T, V Löhneysen H. Importance of in-plane anisotropy in the quasi-two-dimensional antiferromagnet BaNi2V2O8.
PHYSICAL REVIEW LETTERS 2007;
99:137206. [PMID:
17930632 DOI:
10.1103/physrevlett.99.137206]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Indexed: 05/25/2023]
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 c. At micro(o)H* approximately 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* 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.
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