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This report is on the growth of Fe3O4 nanofilms on Al2O3(0001) and MgO(001) substrates with and without the presence of an external magnetic field using a pulsed injection metallorganic chemical vapour deposition (PI MOCVD) technique. The effects of growing magnetic oxide nanofilms in a 1 T field have been examined using various instrumental methods. It was found that the application of a magnetic field during PI MOCVD does not drastically alter the crystalline texture, surface morphology, and film thickness, but it significantly modifies the Fe3O4 film magnetisation and coercive field. Moreover, it was shown that the application of a 1 T field during the cooling of the sample also improves the magnetic properties. We believe that the large external field orients the magnetic spin structure at high temperatures (during growth or the initial stages of cool down) and that cooling through local magnetic ordering temperatures at Fe3O4 defect sites subsequently favours a ferromagnetic spin alignment. The control of magnetic properties of magnetite nanofilms by the application of magnetic fields during growth opens up new routes towards the fabrication and application of magnetic thin film devices.

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.

Dense ceramic mixed ionic and electronic conducting membranes have been deposited by atmospheric spray-pyrolysis technique onto porous ceramic substrates. Perovskite oxide layers, i.e. manganites La1−xSrxMnO3, ferrites La1−xSrxFe1−y(Co,Ni)yO3, gallates La1−xSrxGa1−y(Co,Ni,Fe)yO3, cobaltites La1−xSrxCoO3 and related perovskites such as lanthanum nickelate La2NiO4 layers have been prepared. The structure, morphology and composition of the layers were characterised by XRD, SEM and WDS, respectively. Density and gas tightness of the layers were studied as a function of deposition process parameters, film thickness (from ∼0.5 to ∼3 μm) and preparation procedure. The presence of cracks and defects due to thermo-mechanical stresses applied during or after the preparation process were correlated with the membrane composition and the corresponding thermal expansion coefficient differences between substrates and membranes.

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.

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 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.

Millimeter wave bridge technique for nondestructive material homogeneity characterization is described. The idea of this technique is the local excitation of millimeter waves in testing material and the measurement of the transmitted amplitude and phase in it different places. Some results of the homogeneity measurements for the dielectric substrates are presented.

Bilayers composed from a YSZ or CeO 2 buffer layer and a YBCO film were in situ grown on monocrystalline sapphire, MgO. silicon, vicinally polished sapphire and MgO substrates by single source pulsed injection CVD. Zr. Ce. Y. Ba and Cu 2,2,6,6-tetramethyl-3,5-heptandionates dissolved in organic solvent were used for film deposition. CeO 2 /YBCO bilayers on sapphire were grown epitaxially and exhibited critical current densities up to 10 6 A/cm 2 at 77 K. YSZ and CeO 2 buffer layers on MgO substrates did not improved the properties of YBCO layers compared with YBCO films deposited directly on MgO surface; however, interesting microstructural properties of these heterostructures were found. Homogeneous YSZ films were also deposited on large Si substrates (3 inches in diameter).

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 .

Epitaxial YBCO thin films have been grown on MgO, SrTiO 3 and NdGaO 3 substrates by a new process (injection MOCVD). Droplets (few μ1) of a solution of Y, Ba and Cu β-diketonates in monoglyme are injected into an evaporator through a fast micro electro-valve driven by a computer. Growth rates more than ten times higher than those obtained by the conventional MOCVD process have been obtained in this first step of experiments (>3 μ m h −1 ). The best films obtained so far have T c >90 K and J c >3×10 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.

Praseodymium oxide Pr2O3 (and Pr6O11) layers were deposited by innovative pulsed injection MOCVD technique on Si(100) in the temperature range 400-750°C. Praseodymium 2,2,6,6-tetramethyl-3,5-heptanedionate dissolved in monoglyme (1,2-dimethoxyethane) or toluene was used as precursor material. The influence of deposition conditions on film composition, growth rate, crystallization and surface roughness has been investigated. The main parameters influencing film composition and properties were substrate temperature and partial oxygen pressure during deposition. The presence of molecular oxygen in the reactor leads to the growth of Pr6O11 as the most stable phase or its mixture with PrO2, while deposition in inert atmosphere (Ar, 2 torr) allows to obtain Pr2O3 films which were amorphous or crystalline depending on the deposition temperature. Crystallized (polycrystalline) Pr2O3 films can be obtained at the growth temperatures 650°C and higher, while crystalline Pr6O11 films grow starting 400°C. Ex-situ annealing (750°C, vacuum, 2 hours) of the amorphous Pr2O3 films leads to film crystallization. Step coverage study has been performed for amorphous and crystallized Pr2O3 films. Electrical properties of thin (∼10 nm) Pr2O3 films were investigated and encouraging EOT (equivalent oxide thickness), leakage current data have been obtained.

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.