The random alloy GaInP2 exhibits the 43mBAR point group symmetry and t
hus does not posses a unique polar direction. In contrast, spontaneous
ly ordered GaInP2 exhibits the 3m point group symmetry which can give
rise to pyroelectricity along the 3-fold symmetry axis or ordering dir
ection. Due to the similarity between the Ga and In cations, any tempe
rature variation induced polarization is expected to be very small com
pared with typical pyroelectrics such as hexagonal CdS. Our study yiel
ds the first experimental evidence for pyroelectricity in single varia
nt spontaneously ordered GaInP2. The experiments involve low frequency
laser heating and pyroelectric current measurement using a lock-in de
tection technique.