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We report on pulse-injection metal organic chemical vapor deposition (PI-MOCVD) and characterization of Zn 1 - x Co x O films on (1 1 0 2) sapphire substrates. The use of Zn(tmhd) 2 and Co(tmhd) 3 precursors produces high-quality films in which Co 2 + ions replace Zn 2+ without disrupting the ZnO lattice. The Zn 1 - x Co x O films are magnetic at room temperature for x ⩽ 0.10 and the magnetic moments are particularly large for small Co doping concentrations ( 18.9 μ B / Co for x = 0.01 and 6.5 μ B / Co for x = 0.02 ). These large moments and the decrease of the saturation moment with increasing Co content cannot be explained by the formation of Co clusters. We instead believe that the magnetic behavior of the PI-MOCVD grown samples is an intrinsic property of the Zn 1 - x Co x O films.

This work is devoted to deposition of alumina–silica films using an innovative pulsed injection metal organic chemical vapour deposition technique and aluminium tri( iso -propoxide) (Al( i -OPr) 3 ) and tetraethoxysilane (TEOS) as precursors. The deposited aluminium silicate films have been characterised by scanning electron microscopy, infrared spectroscopy, X-ray diffractometry and capacitance–voltage ( C – V ) measurements. The investigation of the deposition at different Si/Al ratios and substrate temperatures has shown that the growth rate increases with the increase of Al( i -OPr) 3 proportion in solution and decreases as the proportion of TEOS increases. We have also shown that aluminium content in the film increases at lower deposition temperatures while silicon content increases at higher temperatures. The permittivity of the films determined from C – V measurements decreases with increasing substrate temperature. It was found that films deposited at substrate temperatures of 600 or 700 °C and with the highest Si/Al ratio have the lowest dielectric permittivity. This research should be useful for further development of MOCVD technology for the deposition of aluminosilicate-based dielectric materials with controlled dielectric permittivity.

High quality epitaxial La1−xSrxMnO3 films were deposited by pulsed injection metal organic chemical vapor deposition, using as precursor materials metal-2,2,6,6-tetramethyl-3,5-heptandionates dissolved in monoglyme. The influence of various deposition conditions, substrate material and film thickness on film properties was investigated. The best films were deposited on LaAlO3 substrates at 825 °C: films exhibited a sharp semiconductor–metal transition and high magnetoresistance (∼40%) at a close-to-room temperature and in a rather low field of 1.5 T. In-situ or ex-situ high-temperature annealing in oxygen increased the temperature of semiconductor–metal transition, but decreased the magnetoresistance and the temperature coefficient of resistance. Biaxial strain imposed by the lattices’ mismatch was clearly observed in thinner La1−xSrxMnO3 films on perovskite substrates. Tensile strain was present in the films on SrTiO3 and compressive strain in the films on LaAlO3 (and less clearly on NdGaO3). Both tensile and compressive strains decreased the temperature of electric transition and the values of magnetoresistance. The strain was completely relaxed in the films more than ∼100 nm thick.

The possibilities of a new single source injection metalorganic chemical vapor deposition technique were demonstrated for in situ growth of YBa 2 Cu 3 O 7 films of very high crystalline and transport quality. Precisely controlled microamounts of organometallic β-diketonates dissolved in an organic solvent were injected sequentially into the evaporator by means of a computer-driven injector and the resultant vapor was transported into the deposition zone. Accuracy of microdosing (within 5%) and nonselective flash-like evaporation of the precursors were the main factors for obtaining a reproducible vapor phase composition in spite of poor stability of the Ba precursor. The influence of vapor phase composition on film properties was investigated. After the optimisation of deposition conditions, the YBa 2 Cu 3 O 7 films with very high critical current density up to (6–7)×10 6 A/cm 2 at 77 K were reproducibly grown on LaAlO 3 (0 0 1).

We report on large external magnetic field effects during pulsed injection metal-organic chemical vapor deposition of magnetite films on MgO(001). The application of a 1 T field during the growth process significantly increases the saturation magnetization of magnetite by 150%–220% at a deposition temperature of 550 and 600 °C, while the enhancement of the remanent magnetization is even larger. This anomalous magnetic field effect does not drastically alter the crystalline texture, surface morphology, and film thickness of magnetite, but is explained by a suppression of antiphase-boundary formation during film growth.

We report on large magnetic moments of up to 18.9μB∕Co in Co-doped ZnO films grown by pulse-injection metal organic chemical vapor deposition. The magnetic moment saturates easily in perpendicular magnetic fields and is considerably reduced when the magnetic field is applied parallel to the film plane. The saturation moment is largest for a small Co doping concentration of 1% and persists up to a temperature well above 900K. These extraordinary magnetic attributes cannot be explained by the spin-only moment of Co2+ ions or Co cluster, but suggest the formation of orbital states in a defect-related impurity band.