Spin transition properties of metal (Zn, Mn) diluted Fe(phen)2(NCS)2 spin-crossover thin films

Abstract

We report here the effect of metal (Zn and Mn) dilution on the spin transition of Fe(phen)2(NCS)2 thin film spin-crossover (SCO) complex. The SCO complexes are deposited on glass and indium-tin-oxide (ITO) coated glass by dip-coating technique. The growth of the films is clearly confirmed by the appearance of the sharp optical absorption band at 521–540 nm corresponding to 1A1g to 1T1g ligand field absorption of the SCO complex. Although the microstructure of the films remains unaffected by metal dilution, substitution of Fe(II) by either Zn(II) (diamagnetic) or Mn(II) (paramagnetic) results in subtle changes in the bonding environment of the host metal as inferred form X-ray diffraction and Raman studies. The high spin to low spin (or vice versa) transition can be triggered either by electric field or magnetic field as revealed in the measured current (I)–voltage (V) profile or magnetization data of the films. The data further shows the effect of metal dilution on the spin transition temperatures(T1/2), produced hysteresis loop width and loop area, which are the crucial parameter for fabricating spin-based room temperature switching devices.