  We investigate the effect of hydrostatic pressure on temperature dependence
of magnetization and also the influence of magnetic field on linear thermal
expansion in polycrystalline Pr0.6Sr0.4MnO3, which is ferromagnetic at room
temperature (TC = 305 K) but its magnetization undergoes an abrupt decrease at
TS = 89 K within the ferromagnetic state. Normal and inverse magnetocaloric
effects around TC and TS, respectively, were reported earlier in this single
phase compound [D. V. M. Repaka et al., J. Appl. Phys. 112, 123915 (2012)]. The
thermal expansion shows an abrupt decrease at TS in zero magnetic field but it
transforms into an abrupt increase at the same temperature under 7 T, which we
interpret as the consequence of magnetic field-induced structural transition
from a low-volume monoclinic (I2/a symmetry) to a high volume orthorhombic
(Pnma symmetry) phase in corroboration with a published neutron diffraction
study in zero magnetic field. While the external magnetic field does not change
TS, application of a hydrostatic pressure of P = 1.16 GPa shifts the magnetic
anomaly at TS towards high temperature. The pressure induced shift of the
low-temperature anomaly (deltaTS = 27 K) is nine-times more than that of the
ferromagnetic Curie temperature (deltaTC = 3K). Our results suggest that while
hydrostatic pressure stabilizes the low temperature monoclinic phase at the
expense of orthorhombic phase, magnetic field has an opposite effect.
