One-dimensional Fe(II) chains with 1,2,4-triazole as bridging ligands present the LIESST effect; i.e. their spin state switched from low-spin to high-spin after light irradiation at low temperature. This account summarizes the findings in this area of photomagnetism where 57Fe Mössbauer spectroscopy was used as a primary detection tool of the LIESST effect.
Garcia, Y., Renz, F., & Gütlich, P. (2016). LIESST effect in Fe(II) 1,2,4-triazole chains. Current Inorganic Chemistry, 6, 4-9. https://doi.org/10.2174/1877944105666150910195707 (Original work published 2016)