Re-appearance of antiferromagnetic ordering with Zn and Ni substitution in La_{2-x}Sr_xCuO_4

TL;DR

This study investigates how Zn and Ni substitutions affect antiferromagnetic order in La_{2-x}Sr_xCuO_4, revealing that Ni can restore antiferromagnetism and induce a transition from superconductivity to magnetic order.

Contribution

It demonstrates that Ni substitution can recover antiferromagnetic order in lightly doped La_{2-x}Sr_xCuO_4, a novel finding in the context of impurity effects on cuprate magnetism.

Findings

Zn suppresses Néel temperature in parent compound.

Ni doping recovers Néel temperature in lightly doped samples.

Heavy Ni doping leads to spin glass behavior at low temperatures.

Abstract

The effects of nonmagnetic Zn and magnetic Ni substitution for Cu site on magnetism are studied by measurements of uniform magnetic susceptibility for lightly doped La_{2-x}Sr_xCu_{1-z}M_zO_4 (M=Zn or Ni) polycrystalline samples. For the parent x=0, Zn doping suppresses the N\'{e}el temperature T_N whereas Ni doping hardly changes T_N up to z=0.3. For the lightly doped samples with T_N~0, the Ni doping recovers T_N. For the superconducting samples, the Ni doping induces the superconductivity-to-antiferromagnetic transition (or crossover). All the heavily Ni doped samples indicate a spin glass behavior at \~15 K.