Vacuum deposition of high-quality thin films displaying spin transition near room temperature
We report on [Fe(HB(tz)3)2] (tz = triazolyl) (1) thin films with thicknesses in the range of 20–200 nm, which were thermally evaporated on fused silica substrates. Using X-ray diffraction, Raman spectroscopy, UV spectrophotometry, magnetometry and atomic force microscopy, we show that the as-deposited amorphous films can be recrystallized by means of solvent–vapour annealing. The resulting crystalline films are dense, homogenous, highly oriented (with the orthorhombic c-axis normal to the substrate) and exhibit an abrupt and fully complete spin transition around 338 K for each film thickness. The films show stable morphology and spin crossover properties upon thermal cycling and also upon long-term storage in ambient air providing appealing prospects for possible applications in a range of nanoscale devices.