Singlet ground state in the spin-1/2 dimer compound Sr3Cr2O8

TL;DR

This study investigates the magnetic properties of Sr3Cr2O8, revealing a spin singlet ground state with a significant excitation gap and weak interdimer interactions, supported by susceptibility and specific heat measurements.

Contribution

The paper provides experimental evidence of a spin singlet ground state and quantifies the excitation gap and interdimer coupling in Sr3Cr2O8, advancing understanding of its magnetic behavior.

Findings

Spin singlet ground state confirmed in Sr3Cr2O8

Excitation gap of approximately 62 K identified

Weak interdimer coupling estimated at 6 K

Abstract

Magnetic susceptibility and specific heat versus temperature measurements on polycrystalline samples of Sr3Cr2O8 and the isostructural, nonmagnetic compound Sr3V2O8 are reported. A Curie-Wiess fit to the high-temperature susceptibility data for Sr3Cr2O8 indicates that the Cr atoms are in the rare Cr^5+ (Spin S = 1/2) valence state as expected from the composition. The ground state was found to be a spin singlet with an excitation gap Delta/k_ B = 61.9(1) K to the magnetic triplet states, and a weak interdimer coupling of 6(2) K was inferred. The specific heat and susceptibility measurements on Sr3V2O8 reveal a phase transition at 110 K which is evidently a structural transition.