Lattice coupled first order magnetoresistance transition in an A-type antiferromagnet: Pr${}_{0.46}$Sr${}_{0.54}$MnO${}_3$

Abstract

We investigated magnetic, magnetotransport and magnetostriction properties of the A-type antiferromagnet Pr${}_{0.46}$Sr${}_{0.54}$MnO${}_3$ which undergoes a first order paramagnetic-antiferromagnetic transition below T${}_N$ = 210 K while cooling and T${}_N$ = 215 K while warming. The zero field (${\mu }_0$H = 0 T) resistivity shows a sudden jump at T${}_N$ and a small bump around T${}_{max}$ = 220 K (\TEXTsymbol{>} T${}_N$). T${}_N$ shifts down and T${}_{max}$ shifts up with increasing ${\mu }_0$H. Magnetoresistance as high as -45-57 % at 7 T is found in the temperature range 180 K-230 K. Isothermal measurements indicate that the field induced antiferromagnetic to ferromagnetic transition below T${}_N$ is accompanied by a rapid decrease of the resistivity but increase of volume ($\Delta$V/V = +0.25 % at 180 K and 13.7 T). This lattice coupled magnetoresistance transition is suggested due to the field induced structural transition from the low volume orthorhombic to the high volume tetragonal structure.

arXiv comment10 pages, 5 figures, submitted to Phys. Rev. B