EPR spectrum and magnetic ordering of copper orotate

An x-ray diffraction study and measurements of the EPR spectrum of a copper orotate single crystal [Cu(C5H3N2O4)(H2O)(2)] are carried out. At room temperature a one-center EPR spectrum of orthorhombic symmetry is observed. The extremal values of the g factors are determined. Low-temperature broadening of the resonance lines is observed. It is assumed that it is due to the formation of short-range antiferromagnetic order, which arises when the temperature approaches the Neel point T-N = 3.2 K. (C) 2005 American Institute of Physics.