Synthesis and physical properties of single crystals of zeolite-like aluminophosphates of the AFI type

The improvement of the procedure employed for hydrothermal synthesis of aluminophosphates of the AFI type (AlPO 4 ) with the use of triethanolamine as a structure-forming template made it possible to grow large-sized AFI single crystals of high optical quality in the form of hexagonal prisms with a size of up to 2–3 mm along the c axis. The dc electrical conductivity and infrared spectra of the AFI crystals thus obtained were measured.