Anomalous critical behavior of NaV2O5

The temperature dependences and critical behavior of the dielectric constan t were studied in NaV2O5 along the c axis in a frequency range of 1 MHz-1GH z and a temperature range of 4.2-300 K. An analysis of the data obtained, a long with literature data on the heat capacity, magnetic losses, and the ul trasound velocity, indicates that the various physical quantities demonstra te similar temperature dependences in the vicinity of the transition, which corroborates the conclusion on the universality of the critical behavior i n NaV2O5. Deviations from the predictions of the standard theory of second- order phase transitions were found, such as the asymmetry of the critical b ehavior above and below the transition and the presence of an anomalous bas e line. (C) 2001 MAIK "Nauka/Interperiodica".