SPECIFIC-HEAT JUMP IN METALS UNDER QUANTIZING MAGNETIC-FIELDS

The specific heat is calculated for a three-dimensional electron gas i n metals under quantizing magnetic fields taking into account magnetic interactions between conduction electrons (the Shoenberg effect). Und er the conditions of the nonlinear de Haas-van Alphen (dHvA) effect th e temperature jump in specific heat at a diamagnetic phase transition is calculated. The jump occurring at the magnetic field corresponding to the centre of the dHvA period is about of a few percent of the spec ific heat in the absence of magnetic field. In gold and copper it is p redicted to be larger than the maximal value of the change observed du ring a.c. temperature measurements in heat capacity of beryllium in a magnetic field. It is shown that the jump substantially increases with increasing magnetic field. Limiting fields for existence of diamagnet ic phase transitions at any temperature; as well as transition tempera tures in gold and copper at certain fields, are estimated and it is fo und that the latter coincide with the measured values.