We report here thermal and non linear optics measurements: Photoinduced Second Harmonic Generation (PISHG) and Two Photon Absorption (TPA) measurements in the skutterudite RFe4Sb12 (R=Ce,La) and Ce0.7Fe3.5Ni0.5Sb12. The results show existence of important signal in LaFe4Sb12 compared to the CeFe4Sb12. At the same time the third-order Two-Photon Absorption (TPA) possesses maximums at low temperature. The introduction of Ni into the CeFe4Sb12 materials decreases clearly the PISHG and TPA signal.
Measurements of transport and non-linear optical properties in magnetic semiconductors Pb1-xRxX (R=Pr, Yb and X=S, Se, Te at x≈1-3%) were performed to elucidate an influence of magnetic ions on behavior of the charge carriers.
It was shown that nonlinear optical methods may be used as a sensitive tool for investigation of electron-phonon an harmonicity near the low temperature semiconductor isolator phase transformation. The presence of the minimum in Pb1-xPrxTe at about Tρmin = 50 K in the temperature dependence of the resistivity r(T) is due to metal-semiconductor transition. Particularly with increasing of electron-phonon interactions indicated by temperature dependent Debye term (parameter β), one can observe an increase of two-photon oscillator strengths.