Magnetodielectric coupling of a polar organic-inorganic hybrid Cr(II) phosphonate

Cr[(H3N-(CH2)(2)-PO3)(Cl)(H2O)] represents a rare example of a polar organic-inorganic hybrid material that exhibits a canted antiferromagnetic order below T-N=5.5 K. The unusual coexistence of a polar crystal structure and magnetic order triggered our investigation of the magnetodielectric coupling. The coupling is evidenced by an anomaly in the temperature dependence of the dielectric constant epsilon below the Neel temperature. The magnetocapacitance is enhanced by one order of magnitude below T-N. The main characteristics of the magnetodielectic response are interpreted by Landau theoretical coupling terms.