$A$-cation control of magnetoelectric quadrupole order in $A$(TiO)Cu${}_4$(PO${}_4$)${}_4$ ($A$ = Ba, Sr, and Pb)

K. Kimura, M. Toyoda, P. Babkevich +5

Ferroic magnetic quadrupole order exhibiting macroscopic magnetoelectric activity is discovered in the novel compound $A$(TiO)Cu${}_4$(PO${}_4$)${}_4$ with $A$ = Pb, which is in contrast…