Ap. Ramirez et al., SPECIFIC-HEAT STUDY OF THE 2-DIMENSIONAL FRUSTRATED FERROMAGNET RB2CU1-XCOXF4, Journal of magnetism and magnetic materials, 140, 1995, pp. 1713-1714
Specific-heat experiments are performed on single crystals of the two-
dimensional random-exchange magnet Rb2Cu1-xCoxF4, with x = 0.08, 0.11
(axial ferromagnets), 0.22 and 0.28 (spin glasses). In the ferromagnet
s, two distinct ordering events are observed, the upper one at about 5
K marking the onset of ferromagnetic order along the c-axis, and the
lower one at 0.79 K associated with short-range ordering of transverse
spin components.