Zero-point spin fluctuations and anomalies in heat capacity and thermal expansion in low-temperature phase transitions in weak band magnets

The effect of zero-point spin fluctuations on the electron heat capacity and the electron component of the thermal expansion coefficient of low-temperature weak band magnets is considered. It is found that this effects boils down to a suppression of thermal fluctuations. It is shown that analysis of experimental data on scattering of polarized neutrons with spin flip is essential for estimating the amplitude of zero-point spin fluctuations.