Effect of the metal dilution on the thermal and light-induced spin transition in [FexMn1−x(bpp)2](NCSe)2: When T(LIESST) reaches T1/2

International audience; The thermal and light-induced spin transition in [FexMn1−x(bpp)2](NCSe)2 (bpp = 2,6-bis(pyrazol-3-yl)pyridine) has been investigated by magnetic susceptibility, photomagnetism and diffuse reflectivity measurements. These complexes display a thermal spin transition and exhibit the light-induced excited spin state trapping (LIESST) effect at low temperature. For each mixed-crystal system, the thermal spin transition temperature, T1/2, and the relaxation temperature of the photo-induced high-spin state, T(LIESST), have been systematically determined. It appears that T1/2 decreases with the metal dilution while T(LIESST) remains unchanged, suggesting that the two interco…