Effect of magnesium doping on the orbital and magnetic order in LiNiO2

Abstract

In LiNiO2, the Ni3+ ions, with S=1/2 and twofold orbital degeneracy, are arranged on a trian- gular lattice. Using muon spin relaxation (MuSR) and electron spin resonance (ESR), we show that magnesium doping does not stabilize any magnetic or orbital order, despite the absence of interplane Ni2+. A disordered, slowly fluctuating state develops below 12 K. In addition, we find that magnons are excited on the time scale of the ESR experiment. At the same time, a g factor anisotropy is observed, in agreement with $|3z^2-r^2>$ orbital occupancy.

References in corpus (5)

• Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2
• Charge disproportionation and collinear magnetic order in the frustrated triangular antiferromagnet AgNiO2
• Ground-state valency and spin configuration of the Ni-ions in nickelates
• Anomalous temperature evolution of the internal magnetic field distribution in the charge-ordered triangular antiferromagnet AgNiO2
• Spin excitations in the antiferromagnet NaNiO2