Quantum Phase Transition from a Spin-liquid State to a Spin-glass State in the Quasi-1D Spin-1 System Sr1-xCaxNi2V2O8

TL;DR

This study demonstrates a quantum phase transition in a quasi-1D spin-1 system from a spin-liquid to a spin-glass state induced by minimal Ca substitution, revealing new magnetic ground states.

Contribution

It provides experimental evidence of a quantum phase transition caused by Ca doping in Sr1-xCaxNi2V2O8, a quasi-1D spin-1 system, linking doping to magnetic state changes.

Findings

Parent compound exhibits a spin-liquid state with a 26.6 K energy gap.

Ca substitution induces a spin-glass state with increasing freezing temperatures.

Magnetic measurements confirm the transition from spin-liquid to spin-glass ground state.

Abstract

We report a quantum phase transition from a spin-liquid state to a spin-glass state in the quasi-one dimensional (1D) spin-1 system Sr1-xCaxNi2V2O8, induced by a small amount of Ca-substitution at Sr site. The ground state of the parent compound (x = 0) is found to be a spin-liquid type with a finite energy gap of 26.6 K between singlet ground state and triplet excited state. Both dc-magnetization and ac-susceptibility studies on the highest Ca-substituted compound (x = 0.05) indicate a spin-glass type magnetic ground state. With increasing Ca-concentration, the spin-glass ordering temperature increases from 4.5 K (for the x = 0.015 compound) to 6.25 K (for the x = 0.05 compound). The observed results are discussed in the light of the earlier experimental reports and the theoretical predictions for a quasi-1D spin-1 system.