MAGNETIC ORDERING IN DILUTE YTb AND YEr ALLOYS

The Low Temperature Specific Heat of Dilute Er–Y Alloys

“…The linear variation of T m with x extrapolates to a value of about 1 (or less) at% Er. The values of T m agree quite well with the Ne  el temperatures derived from neutron diffraction measurements [1]. It would appear then that the anomalies in the bulk measurements correspond to long-range order helical antiferromagnetism and not to the onset of a spin-glass phase.…”

“…The magnetic phase diagram of Er±Y alloys with Er concentrations between 3 to 10 at% has been determined using a combination of heat capacity measurements and neutron diffraction [1]. This study showed the existence of sinusoidally modulated antiferromagnetism down to the lowest impurity concentration.…”

Random field and random anisotropy effects in defect-free three-dimensionalXYmodels

“…N = 2) with random anisotropy in four dimensions or less. The first are the experiments 5 on SDW alloys which appear to have LRO. The second is the high temperature susceptibility series for the random anisotropy XY model, 23 which gives no indication of an instability of ferromagnetism in four dimensions.…”

“…4 One unresolved issue is whether these arguments can be extended to the SDW case, where there are experiments which indicate the stability of LRO in the presence of pinning. 5 Another controversy involves the existence of the proposed "Bragg glass" phase, 6 which has quasi-long-range order (QLRO).…”