In the present investigation, the changes in the physical properties o
f triglycine sulphate due to the substitution of phosphate ions in pla
ce of sulphate ions in various concentrations have been studied. The p
yroelectric measurements made on the samples of TGS and TGSP revealed
that phosphate substitution enhanced the pyroelectric figure of merit
in the range of compositions studied. The microhardness of TGSP was fo
und to be less than that of TGS.