Leonardo Apostolico

Chemical vapour deposition of group Vb metal phosphide thin films

The atmospheric pressure chemical vapour deposition (APCVD) reaction of VCl4 or VOCl3 with cyclohexylphosphine at substrate temperatures of 600 °C deposits thin films of amorphous vanadium phosphide. The films are black–gold, hard, chemically resistant and conductive. The APCVD reaction of MCl5 (where M = Nb or Ta) with cyclohexylphosphine at 500–600 °C deposits films of crystalline β-MP and at 400 °C–450 °C amorphous films of stoichiometry MP are formed. The MP films are metallic, conductive, adherent and chemically resistant.

Chemical vapour deposition of crystalline thin films of tantalum phosphide

Tantalum phosphide coatings were prepared by chemical vapour deposition reaction of TaCl5 and PH2Cy at 350-500 degreesC. The films are hard, stable to corrosive environments and show reflection properties in the infrared

The reaction of tin(IV) iodide with phosphines: formation of new halotin anions

The reaction of SnI(4) with each of a primary, secondary and tertiary phosphine has been investigated and in none of the cases are simple adducts formed. With Cy(3)P, [Cy(3)PI](+) salts of both [SnI(3)](-) (1) and [SnI(5)](-) (2) are isolated arising from reactions involving both reduction at tin and halogen transfer. With the secondary and primary amines Ph(2)PH and CyPH(2), respectively, additional HI elimination reactions occur and the salts [Ph(2)PH(2)](+)(6)[Sn(3)I(12)](6-) (3), [Ph(2)PH(2)](+)(2)[SnI(6)](2-) (4) and [CyPH(3)](+)(2)[SnI(4)](2-) (5) have been isolated. Compounds 1-5 have been characterised crystallographically.

Single-source CVD routes to titanium phosphide

Treatment of TiCl4 with two equivalents of L (L = PhPH2, Ph2PH, PPh3, CyPH2, Cy2PH, PCy3) resulted in the formation of [TiCl4(L)2]. Reaction of TiCl4 with a stoichiometric amount of 1,2-bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe) and 1,2-bis(diphenylphosphino)propane (dppp) affords [TiCl4(dppm)], [TiCl4(dppe)] and [TiCl4(dppp)], respectively. X-Ray crystal structures of [TiCl4(Cy2PH)2] (5) and [TiCl4(dppe)] (9) have been determined. Low pressure chemical vapour deposition (LPCVD) studies of all the compounds revealed that [TiCl4(L)2] (L = CyPH2, Cy2PH and PCy3) and [TiCl4(dppm)] can form titanium phosphide thin-films on glass.

Dual-source chemical vapour deposition of titanium(III) phosphide from titanium tetrachloride and tristrimethylsilylphosphine

Thin films of titanium(III) phosphide (TiP) have been produced from the dual-source atmospheric pressure CVD reaction of TiCl4 and tristrimethylsilylphosphine. Analysis of the films using EDAX, SEM, glancing angle XRD and XPS is presented.