Anomalousg-Value of a Cr-Trimer Complex, Cr-Propionate {Cr3O(C2H5COO)6(H2O)3}NO32H2O

Abstract

Origin of anomalous g -shift observed in a Cr-trimer complex {Cr 3 O(C 2 H 5 COO) 6 (H 2 O) 3 }NO 3 2H 2 O is discussed. It is found that the Dzyaloshinsky-Moriya interaction in the trimer produces the in-plane g -shift for the triangular trimer plane. The g -shift in magnetic field H 0 is negative with the magnitude of (8/3) D z 2 /{( Δ E ) 2 -( g ⊥ 0 µ B H 0 ) 2 } where D z is the Dzyaloshinsky-Moriya interaction perpendicular to the trimer plane. g ⊥ 0 is in-plane g -value of each Cr 3+ ion, µ B is Bohr magneton and Δ E is the energy gap between the ground and first excited Kramers doublets splitted by the intra-trimer exchange interaction. The observed in-plane g -value 1.89 is well explained by introducing D z of 0.9 K in the trimer.