First-order field-induced transition, magnetoresistance, and giant magnetostriction in single crystals of (La0.4Pr0.6)(1.2)Sr1.8Mn2O7 - art. no. 012407

The well-established paraferromagnetic transition (T-c) accompanied by a se miconductor-metal transition in the bilayer manganite La1.2Sr1.8Mn2O7 was f ound to he suppressed in single crystals of (La0.4Pr0.6)(1.2)Sr1.8Mn2O7. Ho wever, a first-order field-induced transition was observed accompanied by a huge decrease of the c-axis resistance by a factor of one million. The mag netoresistance data correlate well with an equally large negative magnetost riction. In addition, strong anisotropic properties are observed. The data reflect the presence of unusual interplay among spin, charge, and orbital d egrees of freedom in this layered structure.