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Thin films of ZnO have been grown by low-pressure MOCVD using methylzinc isopropoxide, MeZn(OPi), and methylzinc tert-butoxide, MeZn(OBu*), in the absence of an added oxygen source. The films were grown on to glass substrates in the temperature range 250-400 "C with growth rates of between 0.2 and 4.4 pm h-'.

This paper presents a study of moisture absorption-desorption effects in single lap adhesive joints. Experiments were carried out to characterise the moisture uptake of the single part epoxide adhesive, FM73. Tensile testing of single lap joints manufactured from aluminium alloy 2024 T3 and O and FM73 adhesive was carried out after the joints were exposed to different conditioning environments. The experimental results revealed that the failure strength of the single lap joints with 2024 T3 adherends progressively degraded with time when conditioned at 50°C, immersed in water.However, the joint strength almost completely recovered after moisture was desorbed.The single lap joints with 2024 O adherends showed decreased strength for 28 days of conditioning, after which strength recovered, reaching a plateau after 56 days. Again, strength almost completely recovered on desorption of moisture. The strength recovery of the joints, after desorption of moisture, showed that the degradation of the adhesive was largely reversible. Analysis of the failure surfaces revealed that the dry joints failed cohesively in the adhesive layer and that the failure path moved towards the interface after conditioning. The failure mode then reverted back to cohesive failure after

Thin films of hafnium oxide (HfO 2 ), gadolinium oxide (Gd 2 O 3 ), and praseodymium oxide (PrO x ) have been deposited by liquid injection atomic layer deposition (ALD) and for comparison, have also been deposited by ªthermalº metal-organic (MO) CVD using the same reactor. The ALD-grown films were deposited on Si(100) over a range of substrate temperatures (150±450 C) using alternate pulses of [Hf(mmp) 4 ], [Gd(mmp) 3 ], or [Pr(mmp) 3 ] (mmp = OCMe 2 CH 2 OMe) and water vapor. X-ray diffraction (XRD) analysis showed that as-grown films of HfO 2 were amorphous, but these crystallized into the monoclinic phase after annealing in air at 800 C. XRD analysis showed that as-grown Gd 2 O 3 and PrO x films had some degree of crystallinity. Residual carbon (0.8±3.3 at.-%) was detected in the HfO 2 and PrO x films by Auger electron spectroscopy (AES), but not in the Gd 2 O 3 films. The self-limiting behavior of the precursors was investigated at 225 C by varying the volume of precursor injected during each ALD cycle and, in each case, oxide growth was not fully self-limiting. We propose a mechanism for this involving b-hydride elimination of the mmp group, and also propose some general mechanistic principles which may influence the growth of oxides by ALD using other precursors.

The crystal structure of the volatile bismuth alkoxide tris(1-methoxy-2-methyl-2-propanolato)bismuth(III), Bi(OCMe 2 -CH 2 OMe) 3 , 1, has been determined by single crystal X-ray diffraction (XRD). The complex is mononuclear, containing a sixcoordinate Bi III atom in a distorted octahedral environment. Using a solution of 1 in heptane, thin films of bismuth oxide have been deposited by liquid injection metal±organic (MO) CVD. Deposition was carried out over a wide range of substrate temperatures (250±550 C) and, using Auger electron spectroscopy (AES), films were shown to be pure bismuth oxide (Bi 2 O 3 ) with no detectable carbon.