X-ray powder diffraction and LIESST-effect of the spin transition material [Fe(bpp)2](NCS)2 · 2H2O

Sample history dependent structural bistability of spin transition material [Fe(bpp)2](NCS)2 · 2H2O has been characterised at room temperature from XRD. Relatively prolonged exposure of the sample to X-rays caused a structural change. LIESST and Reverse-LIESST effects, characterised by 57Fe Mössbauer spectroscopy, have been observed in this material. This material is a remarkably fluid system with respect to its response to thermal cycling, both electronically and structurally.