Growth, structural, thermal, electrical and nonlinear optical properties of Yb3+ doped KTiOPO4

• The transparent KTP:Yb crystal were grown by the TSSG technique.
• The weak EPR signal is attributed to the less Ti3+ center in KTP:Yb.
• Low ionic conductivity of 9.0435×10−7 S/cm was observed for Yb3+ doped KTP.

The KTiOPO4:Yb (KTP:Yb) crystal has been grown by flux growth at high temperature (~ 1243−1223K ). KTP:Yb crystallizes in the orthorhombic crystal system with Pna21 space group. Ytterbium presence was analyzed in the grown crystal by EDAX analysis. The existence of Ti3+ color center has been evaluated using electron paramagnetic spin resonance spectrum. The Raman spectroscopic techniques were used to study the effect of Yb3+ in KTP crystal. Thermal diffusivity, thermal conductivity and specific heat capacity of grown crystal were studied. At low frequency, the dielectric constant decreases sharply in the frequency region of 104 Hz. The electrical conductivity along the [001] is low (9.0435×10−7 S/cm) for 60 kHz at 300 K. The temperature dependent variation of electric conductivity was found for [010] and [001] of KTP:Yb. The effect of Yb3+ doping in second harmonic generation of KTP was studied.