Magnetic domains in the vicinity of shear bands produced by bending were investigated to study the effect of furnace annealing on the domain structures. Domain wall spacings were measured as a function of annealing time at several temperatures. The same specimens were also used to evaluate the degree of embrittlement by measuring the bending fracture strains.

The reduction of dislocation density in heteroepitaxial III-V compound films on Si substrates has been studied using MOCVD (Metal-Organic Chemical Vapor Deposition). High-quality GaAs films on Si, with a dislocation density of about 106 cm−2, have been obtained by combining strained-layer superlattice insertion and thermal cycle annealing. Reduction of dislocation density in the III-V compounds on Si is discussed based on a simple model, where dislocation annihilation is assumed to be caused by dislocation movement under thermal and misfit stress. As a result of dislocation density reduction, high-efficiency GaAs-on-Si solar cells with total-area efficiencies of 18.3% (AM0) and 20% (AM1.5), and red and yellow emissions from InGaP-on-Si light-emitting diodes have been realized. Moreover, future prospects of heteroepitaxy of III-V compounds on Si are also discussed.

Bridged quasi–one-dimensional macrocyclic transition metal complexes [MacM(L)]n using phthalocyanine (Pc), tetrabenzoporphyrine (TBP), 1,2- and 2,3-naphthalocyanines (1,2-Nc; 2,3-Nc) as macrocycles (Mac) with M = e.g., Fe, Ru, Co and L = e.g., pyrazine (pyz), 1,4-diisocyanobenzene (dib), tetrazine (tz) exhibit interesting electrical properties. Regardless of the size of the bridging ligand after either chemical or electrochemical doping stable semiconducting compounds [MacM(L)Xy]n (X = e.g., I2 BF4−, ClO4−…) are formed. For the first time the complete characterization of soluble oligomers [MacM(L)]n (Mac = t-Bu4Pc, M = Ru, L = dib, me4dib) by 1H-NMR spectroscopy is reported. Some of these shish kebab complexes, e.g., [PcM(tz)]n, (M = Fe, Ru) or [MacMCN]n; (Mac = Pc, TBP; M = Co, Fe) exhibit good semiconducting properties without additional external doping. Whether or not these compounds are intrinsic semiconductors will be discussed. The synthesis of oligomeric bridged mixed valence compounds [PcM(III)LPcM(II)L]n, (M = e.g., Fe) is another target of our work. We report here on first results of these oligomers.

NbVO5 is characterized by 51V and 93Nb NMR resonance frequencies strongly upfield shifted when compared to those in model compounds V2O5 and LiNbO3. The chemical shift anisotropy dominates the 51V observed spectrum in a magnetic field of 11.7 T. The asymmetry parameter ηc is 0.2 and the quadrupole coupling constant is relatively small (1 MHz). The quadrupolar Hamiltonian overwhelmingly dominates the 93Nb spectrum (ηQ = 0.9) and the quadrupole coupling constant is huge (16.5 MHz). In agreement with the structure obtained from the x-ray powder diagram the isotropic chemical shift of 51V suggests that NbVO5 is indeed an orthovanadate. Interestingly, in NbVO5 the isotropic chemical shift of 93Nb reveals a better shielding of the 93Nb nucleus and a lower electric field gradient than in LiNbO3. Nb octahedra in NbVO5 are sharing corners whereas they share edges in LiNbO3.

Fluorozirconate glasses are stable with respect to devitrification but have poor chemical durability and only fair mechanical strength. AlF3-based glasses with improved chemical durability and enhanced mechanical strength are reported here. The optical, mechanical, and thermal properties of these glasses are contrasted to the more familiar ZBLAN composition. The infrared edge of these glasses lies at shorter wavelengths than ZrF4-based glasses, but aluminum fluoride glasses offer some interesting opportunities for short-range IR fiber applications such as sensing, remote spectroscopy, and laser power propagation.

The microindenter has proven to be a powerful device in the characterization of the mechanical properties of thin films. The machine has both high resolution in the applied load and penetration depth measurements, as well as the versatility to perform different types of testing. The former provides the capability to deal with extremely thin films, while the latter allows for other mechanical properties, in addition to hardness, to be acquired. Four types of tests, namely indentation, scratch, load relaxation, and indentation fatigue tests can currently be conducted using the microindenter via different operating procedures. Only the scratch and load relaxation techniques will be covered in this paper. In a microscratch test, the normal load, tangential load, scratch length, and acoustic emission are monitored simultaneously during an entire scratch process for the purposes of measuring the critical load and studying the failure mechanisms of the deposited films. The adhesion strength, scratch hardness, fracture toughness, and friction are the mechanical properties which are possible to obtain by using this technique. Results from aluminum, carbon, and zirconia coatings will be discussed. The load relaxation test provides information on the creep properties of the films and results in an empirical constitutive relation between the applied stress and plastic strain rate. The creep properties of DC sputtered Al films will be used as an illustration of this.