Thermal expansion of single-crystalline La0.83Sr0.17MnO3: The importance of temperature-induced strain for the electrical resistivity

Thermal expansion, magnetization, and electrical-resistivity measurements o f single crystalline La0.83Sr0.17MnO3 are presented. A first-order structur al transition occurs at 300 K, transforming the high-temperature rhombohedr al phase into an orthorhombic phase. The paramagnetic to ferromagnetic phas e transition is second order and is clearly revealed as a change in slope o f the linear-thermal expansion Delta l/l at T-c = 265 K. The temperature de rivative of Delta l/l yields the thermal-expansion coefficient alpha; therm odynamic analysis of alpha near T-c reveals isotropic-uniaxial pressure der ivatives of T-c. Strain arising from the structural and magnetic transition s is shown to influence the electrical resistivity. [S0163-1829(99)01103-0] .