Magnetic field induced spin reorientation in the strongly anisotropic antiferromagnetic crystal LiCoPO4

Abstract

Articles you may be interested inSpin reorientation transition and near room-temperature multiferroic properties in a W-type hexaferrite SrZn1.15Co0.85Fe16O27It has been found experimentally that in the strongly anisotropic orthorhombic antiferromagnetic crystal LiCoPO 4 ͑T N = 21.7 K͒ the destruction of antiferromagnetic order by a magnetic field directed along the antiferromagnetism axis H ʈ b occurs in steps by means of three phase transitions: two first-order transitions in the fields H 1 = 118 kOe, H 2 = 224 Oe and one second-order phase transition in the field H 3 = 283 kOe ͑T = 1.7 K͒. A section of magnetic fields ͑H 2 , H 3 ͒ where the magnetization of the crystal varies almost linearly with the field was found. Possible magnetic structures formed in a magnetic field are discussed. The values of the exchange parameters are estimated.

Magnetic order, hysteresis, and phase coexistence in magnetoelectric LiCoPO4

“…These transition fields correlate reasonably well with features observed in the pulsed-field magnetization data of Ref. [28]. The Curie-Weiss temperature, θ CW = 121(1) K, was determined from the inverse magnetic susceptibility (not shown) at 0.5 T applied along b.…”

“…The energy cost associated with the single-ion anisotropy is independent of the phase shift angle. Assuming M S = 3.6 μ B [28] and choosing the phase shift to π/3 the cycloid and ferromagnetic components result in the structure illustrated in Figs. 5(b) and 5(c).…”

“…The maximum field was 25.9 T and thus enabled direct probing of the remaining magnetic phases at high fields indicated by the magnetization data of Ref. [28]. The required crystal orientation and the opening angle of the magnet limited the number of accessible Bragg peaks to (3,0,1), (2,0,1), (1,0,1), (1,0,1), (1,0,0), (0,0,1), and (0,K,0) for K 10.…”

“…Pulsed-field magnetic susceptibility measurements up to 29 T at liquid He temperatures show a number of phase transitions [28]. At ∼12 T, the magnetization jumps to a plateau of 1 3 of its saturation value M S = 3.6 μ B /Co ion.…”

“…In Ref. [28], the values of J bc , J b , and J c were estimated for LiCoPO 4 from the transition field values using a model for the magnetic structures based on magnetization measurements exclusively. Collinear structures with moments along b and propagation vector along c were assumed in all phases.…”