IMPACT OF Ce DOPING ON THE MAGNETIC AND TRANSPORT PROPERTIES OF Y1-xCexSr2Ru0.9Cu2.1O7.9; x = 0.05 AND 0.1

Abstract

The magnetic and transport properties of lightly Ce doped, Y 1-x Ce x Sr 2 Ru 0.9 Cu 2.1 O 7.9(x = 0.05 and 0.1) samples have been studied and their results are compared with the pristine rutheno-cuprate, YSr 2 Ru 0.9 Cu 2.1 O 7.9. The electron doping due to Ce 4+ for Y 3+ ion impacts on the physical properties of the present system. The tetragonal stabilized samples exhibit magneto superconducting properties under zero field cooled condition (H = 10 Oe ) and the diamagnetic onset transition, Td shift slightly towards higher temperature with the increase of "x". Weak antiferromagnetic like hysteresis curves are seen for these samples at 2 K in the magnetic field strength up to ±10 kOe and the magnetization moment, M(μB/ Ru ) decreases with increase of "x". While the magnetic property of the present system is due to canted Ru moments, the superconducting signal originates from CuO 2 plane. Through electrical resistivity measurements we observe that none of the samples exhibit bulk superconductivity down to 2 K. However the x = 0.05 sample reveals lowest resistivity in the entire temperature range than x = 0 and 0.1 samples. The isothermal magnetoresistance, MR(H) measured at different temperatures vary with tuning of "x". While x = 0.1 doped sample shows lower -MR(~ 8%), the pristine sample exhibits maximum -MR(45%) at 2 K under ±90 kOe field condition.