Answers are grounded in this paper and cite their sources.
The dispersion relations for magnetic excitons propagating on the hexagonal sites of double-hcp Pr provide clear evidence for a pronounced anisotropy in the exchange. The energy of the excitations decreases rapidly as the temperature is lowered, but becomes almost constant below about 7 K, in agreement with a random-phase-approximation calculation. No evidence of magnetic ordering has been observed above 0.4 K, although the exchange is close to the critical value necessary for an antiferromagnetic state.
No takes yet. Share an insight, caveat, or question.
Houmann et al. (1975) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: