Effect of trivalent metal ion impurities (Al~(3+), Cr~(3+) and Fe~(3+)) on the growth, structural and physical properties of potassium acid phthalate (KAP) crystals

摘要

Trivalent metal ion (Al, Cr, Fe) doped potassium hydrogen phthalate (KAP) crystals have been grown from aqueous solution at room temperature. Powder XRD and ICP-OES studies confirmed the metal ion doping into KAP crystals. The presence of functional groups in the crystal has been observed by FTIR analysis. Optical transmission studies were carried out by allowing the UV-NIR ray of wavelength between 190 and 1000 nm to pass through the (010) face of the grown KAP crystals. Dielectric constant value of Fedoped KAP at 100 Hz was found to be significantly higher than that of undoped and Cr and Al-doped KAP. TG-DTA studies show the decomposition temperatures to be 255, 270, 258 and 287 °C for pure, Al~(3+), Cr~(3+) and Fe~(3+) doped KAP crystals respectively. Microhardness studies reveal that the Cr~(3+) and Fe~(3+) doped crystals have higher hardness values than that of undoped and Al-doped KAP. The grown crystals were also subjected to second harmonic generation (SHG) efficiency tests.