Magnetization-induced second-harmonic generation in electrochemically synthesized magnetic films of ternary metal Prussian blue analogs

We observed magnetic field effects on transmitted second-harmonic generation (SHG) in electrochemically synthesized ((FexCr1-xII)-Cr-II)(15)[Cr-III(CN)(6)] . 7.5H(2)O magnetic films. These films showed a variety of temperature dependences for SH intensities below magnetic phase transition temperatures (T-C). The SH intensity for x=0.25 increased monotonically with decreasing temperature and that for, x=0.13 exhibited a minimum value around the magnetic compensation temperature under a zero magnetic field. These temperature dependences resembled those of the absolute value of magnetization, indicating that the magnetic strain of the films is responsible for the increase in SH below T-C. In addition, the polarization of SH light was rotated by an applied external magnetic field. The observed SH rotation angle of 1.3degrees was much larger than the Faraday rotation angle of 0.079degrees at 388 nm. This SH rotation can be understood by the mechanism of magnetization-induced SHG caused by interaction between the electric polarization along the out-of-plane of film and spontaneous magnetization. The magnetic linear term [X-ijkL(magn(1))] contributed particularly to the SH rotation. The value of the magnetic linear tensor component relative to the crystallographic tensor component [\X-yyyX(magn(1))\/\X-zyy(cr)], which induced the SH rotation, was 0.023 at 50 K under 10 kOe. (C) 2003 American Institute of Physics.