Utilizing the magnetoelectric (ME) effect, the magnetic space group of GdVO4 has been determined to be I41′a′m′d. The temperature dependence of the ME susceptibility α was measured from 1.6°K to TN=2.43°K. Using a modified molecular-field theory it is concluded, from the temperature dependence of α, that the mechanism(s) underlying the effect can be an electric-field-induced Dzialoshinsky interaction and/or an electric-field-induced g shift. The magnitude of α indicates that the former mechanism is the more likely one. The critical behavior of α was measured in the range 0.977TTN0.999. A critical exponent of β=0. 50±0.05 was found. This is considerably higher than that expected for a three-dimensional two-sublattice Heisenberg model with nearest-neighbor interactions only and is suggestive of higher than first-neighbor exchange interactions which act to enhance the long-range order of the system. Such interactions could have a significant effect on the critical behavior due to the small number of nearest neighbors on the diamond lattice formed by the Gd3+ moments.
ASJC Scopus subject areas
- Condensed Matter Physics