Raman Spectral Properties of β-Co2(OH)3Cl down to the Liquid Nitrogen Temperature

Raman spectra of the geometrically frustrated material sample β-Co2(OH)3Cl have first, to the best of our knowledge, been measured down to liquid nitrogen temperature using the experimental conditions of 10X-objective @ 60 mW and 50X-objective @ 5 mW, respectively. It is found that most Raman bands blueshift with decreasing the sample temperature, agreeing with the thermal expansion effect of common materials, but the Raman spectra from different experimental conditions are slightly different with each other at same temperatures. The difference between them has been explained by the local laser heating effect.