Evidence of phase transition in the condenser photo-emf of CdP2

Temperature dependence of condenser photo-emf V in CdP2 crystals in 290-400 K range was studied for the first time. Sudden change of V temperature dependence, related with superstructure destruction, is observed near 365 K. It is noted that superstructure emerges on the surface of crystals with natural surface of growth and etched one. Destruction of modulated structure takes place in thin near-the-surface layer, disturbed after polishing