Neutron diffraction study of thermal expansion and compressibility of pyridinium nitrate and tetrafluoroborate

Neutron powder diffraction investigations of polycrystalline pyridinium nitrate, tetrafluoroborate and their deuterated analogues in the temperature range of 10 - 290 K and hydrostatic helium pressures up to 330 MPa are presented. Temperature and pressure dependencies of the lattice unit cell parameters and volume are examined. These allow us to obtain the thermal expansion coefficients alpha and the isothermal compressibility coefficients beta for these compounds.