Abstract
Ferroic magnetic quadrupole order exhibiting macroscopic magnetoelectric activity is discovered in the novel compound with = Pb, which is in contrast with antiferroic quadrupole order observed in the isostructural compounds with = Ba and Sr. Unlike the famous lone-pair stereochemical activity which often triggers ferroelectricity as in , the cation in is stereochemically inactive but dramatically alters specific magnetic interactions and consequently switches the quadrupole order from antiferroic to ferroic. Our first-principles calculations uncover a positive correlation between the degree of -O bond covalency and a stability of the ferroic quadrupole order.
- Received 3 April 2017
- Revised 10 December 2017
DOI:https://doi.org/10.1103/PhysRevB.97.134418
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