Magnetic order in the chemically substituted frustrated antiferromagnet CsCrF4

Abstract

The effect of chemical substitution on the ground state of the geometrically frustrated antiferromagnet CsCrF4 has been investigated through a neutron powder diffraction experiment. Magnetic Fe-substituted CsCr0.94Fe0.06F4 and nonmagnetic Al-substituted CsCr0.98Al0.02F4 samples are measured, and magnetic Bragg peaks are clearly observed in both samples. Magnetic structure analysis revealed a 120∘ structure having a magnetic propagation vector kmag=(0,0,1/2) in CsCr0.94Fe0.06F4. For CsCr0.98Al0.02F4, a quasi-120∘ structure having kmag=(1/2,0,1/2) is formed. It is notable that the identified magnetic structure in CsCr0.94Fe0.06F4 belongs to a different phase of ground states from those in CsCr0.98Al0.02F4 and the parent CsCrF4. These results suggest that the Fe substitution strongly influences the ground state of CsCrF4. © 2020 American Physical Society