from the Merck Index:
Monograph number: 372
Title: Aluminum Phosphide.
CAS Registry number: [20859-73-8]
Trade names(s): Celphos (Excel); Phostoxin (Degesch); Quickphos (United Phosphorus).
Molecular formula: AlP
Molecular weight: 57.96
Composition: Al 46.56%, P 53.44%.
Literature references: Prepd from red phosphorus and aluminum powder: White, Bushey, J. Am. Chem. Soc. 66, 1666 (1944); Inorg. Syn. 4, 23 (1953); Montignie, Bull. Soc. Chim. France 1946, 276; from Al and Zn2P3: Wang et al., J. Inorg. Nucl. Chem. 25, 326 (1963). Use as insecticidal fumigant: W. Freyberg, W. Haupt, U.S. pat. 2,117,158 (1938 to Freyberg).
Properties: Dark gray or dark yellow crystals. Cubic zinc blende structure. Must be protected from moist air since it reacts readily to produce phosphine which is highly toxic. d415 2.85 (Montignie); d 2.40 (Wang et al.). Does not melt or decompose thermally at temps up to 1000 deg. Treatment with water and acid produces phosphine in quantitative yields.
Density: 2.85; 2.40
USE: Source of phosphine; in semiconductor research; as fumigant.