Relationship between colossal magnetoresistance and giant magnetostrictionat Curie point in Sm0.55Sr0.45MnO3

The close relationship between magnetic, transport and elastic properties i n Sm0.55Sr0.45 MnO3 compound is found. At Curie point T-c = 126 K we have o bserved a large volume contraction DeltaV/V approximate to 0.1%, an abrupt minimum in the temperature dependence of negative volume magnetostriction o mega (T) and a maximum in the temperature dependence of resistivity rho (T) . We have obtained giant negative volume magnetostriction omega approximate to - 5 x 10(-4) in a relatively low magnetic field B = 0.9 T, which is acc ompanied by a colossal negative magnetoresistance (CMR) equal to 44% in the same magnetic field. These properties are explained by a magnetic two-phas e state. (C) 2000 Elsevier Science B.V. All rights reserved.