A series of colossal magneto resistance (CMR) materials with
compositional formula Pr0.5Sr0.5Mn1-xCrxO3 (x = 0, 0.1, 0.2, 0.3, 0.4) were prepared by sol-gel technique using pure metal
nitrates as the starting materials. These samples were characterized
structurally by X-ray diffraction, FTIR and SEM. All the samples exhibit orthorhombic structure without any
detectable impurities. The bulk densities for all the compositions were
measured from the pellets. The Young’s and Rigidity moduli, Poisson’s ratio and
Debye temperature of all the compositions were calculated with the
experimentally measured ultrasonic longitudinal
and shear velocities at room temperature using pulse transmission
technique. As the materials are porous, zero porous elastic moduli have also
been calculated using a well-known Hasselmann and Fulrath model. The observed variation of elastic moduli with
varying chromium doping concentration has been studied qualitatively.
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