Electrical conductivity measurements on gel grown KDP crystals added with some ammonium compounds

Pure and impurity added [with NH4Cl, NH4NO3, NH4N2PO4, (NH4)(2)CO3 and (NH4)(2)SO4] KDP single crystals were grown by the gel method using silica gels. Electrical conductivity measurements were carried out along both the unique axis and perpendicular directions at various temperatures ranging from 28 to 140 degrees C by the conventional two-probe method. The present study shows that the conductivity in KDP crystals, for all the five dopants considered, increases with the increase in impurity concentration and temperature. Activation energies were also determined and reported.