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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.

Biaxially textured buffer layers and YBa 2 Cu 3 O 7 (YBCO) films were grown on NiO/Ni based substrates by pulsed injection MOCVD. High quality biaxially textured NiO layers have been prepared following an optimised recrystallisation–oxidation process. The yttria stabilized zirconia (YSZ) and its combination with CeO 2 and/or Y 2 O 3 were investigated in the role of buffer layers for YBCO. Thin biaxially textured buffer layers were deposited in a temperature range from 600 to 800 °C. The best superconducting properties correspond to the Ni/NiO/YSZ/Y 2 O 3 /YBCO architecture: YBCO layers were grown epitaxially and exhibited a critical temperature T c ∼90 K ( ΔT c ⩽1 K) and critical current densities J c ⩾5×10 5 A/cm 2 at 77 K.

The single liquid source pulsed injection MOCVD technique was used to deposit high quality heteroepitaxial structures containing YBa 2 Cu 3 O 7-x (YBCO), SrTiO 3 (STO) and La 1-x Sr x MnO 3 (LSMO) layers. Y, Cu, Sr, La, Mn thd complexes (thd-2,2,6,6-tetramethylheptane-3,5-dionate), Ba(thd) 2 (phen) 2 (phen-1,10-phenanthroline) and Ti(i-OPr) 2 (thd) 2 or Ti(i-OEt) 2 (thd) 2 were used as precursor materials and monoglyme (1,2-dimethoxyethane) as a solvent. The deposition of heterostructures was performed in situ or ex situ in a hot wall vertical MOCVD reactor. Various heteroepitaxial structures (STO/LSMO, LSMO/STO/LSMO, STO/YBCO, LSMO/YBCO, STO/LSMO/YBCO, LSMO/STO/YBCO, STO/LSMO/STO/YBCO) were grown and studied.

Biaxially textured YBa 2 Cu 3 O 7 (YBCO) thin films, yttria stabilized zirconia (YSZ) and yttria (Y 2 O 3 ), CeO 2 buffer layers were grown in situ on NiO/Ni based substrates by Pulsed Injection MOCVD (PICVD) using monoglyme solutions of β-diketonates (Cu(thd) 2 , Ba(thd) 2 , Y(thd) 3 , Ce (thd) 2 , Zr(thd) 4 ). High quality textured nickel oxide layers have been prepared by SOE (Surface Oxydation Epitaxy) following an optimized recrystallisation-oxidation process.Thin YSZ/Y 2 O 3 biaxially textured buffer layers (thickness 200nm/200 nm) were deposited in a wide range of temperature (from 600°C to 800°C). Subsequent YBCO layers (thickness 750nm) on Ni/NiO/YSZ/Y 2 O 3 were grown epitaxially (ω-scan of YBCO FWMH=5°) and exhibited critical current densities Jc ≥3.10 5 A/cm 2 with a critical temperature Tc=90K and ΔTc ≤ 1 K. The best results were obtained for deposition temperatures of 600°C for YSZ, 675°C for Y 2 O 3 and 800°C for YBCO.

YBa 2 Cu 3 O 7-x (YBCO) and La 1-x Sr x MnO 3 (LSMO) layers were grown by single liquid source pulsed injection MOCVD technique in hot wall vertical MOCVD reactors. Y, Ba, Cu, Sr, La, Mn thd complexes (thd -2,2,6,6-tetramethylheptane-3,5-dionate) were used as precursor materials and monoglyme (1,2-dimethoxyethane) as a solvent. The influence of deposition temperature and thickness on the properties of films on LaAlO 3 and MgO substrates was studied. Thin YBCO layers deposited at 825 °C on LaAlO 3 substrates exhibited epitaxial quality, sharp superconducting transition (∼0.2 K) and a high critical current density (= 4MA/cm 2 at 77 K). Films on MgO substrates were of lower quality, Epitaxial LSMO films were deposited on various substrates, and the tensile or compressive strains and their influence on the film properties was obvous in thinner films on LaAlO 3 and SrTiO 3 substrates.

Single liquid source pulsed injection MOCVD technique was applied for the deposition of epitaxial SrRuO 3 films and SrRuO 3 /YBa 2 Cu 3 O 7 heterostructures on various monocrystalline substrates (LaAlO 3 , SrTiO 3 , NdGaO 3 , MgO, YSZ, sapphire). Sr, Y, Ba, Cu 2,2,6,6-tetramethyl-3,5-heptanedionates and Ru 2,4-pentanedionate (acetylacetonate) were used as precursor materials, 1,2-dimethoxyethane as a solvent. Deposition conditions were optimised to obtain epitaxial films and heterostructures and the influence of substrate material on films' microstructure and electrical properties was studied. The best SrRuO 3 /YBa 2 Cu 3 O 7 heterostructures which were in-situ deposited at 825 °C exhibited rather sharp superconducting transition at about 91 K and critical current density >10 6 A/cm 2 at 77 K.

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).

Epitaxial YBa 2 Cu 3 O 7 layers with 45° in-plane orientation have been grown by Injection CVD on MgO substrates polished off-axis to within 1.4–1.9° of the [100] direction. This new single-source CVD process is based on computer-controlled injection of precise microdoses of a metal–organic precursor solution into a CVD reactor. A wide range of solution compositions was tested to investigate compositional effects on phase purity, surface morphology, texturing and superconducting properties of the prepared films. The highest quality films with pure 45° texture had a smooth surface, zero resistance T c ( R =0) of 88–89 K, and critical current density J c (77 K) above 10 6 A/cm 2 .

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.