Identification of a Blue Photoluminescent Composite Material from a Combinatorial LibraryA quaternary combinatorial masking strategy was used in conjunction with photolithography to generate compositionally diverse thin-film phosphor libraries containing 1024 different compositions on substrates 2.5 centimeters square. A parallel imaging system and scanning spectrophotometer were used to identify and characterize compositions in the library with interesting luminescent behavior. Optimal compositions were identified with the use of gradient libraries, in which the stoichiometry of a material was varied continuously. This process led to the identification of an efficient blue photoluminescent composite material, Gd3Ga5O12/SiO2. Experimental evidence suggests that luminescence in this material may arise from interfacial effects between SiO2 and Gd3Ga5O12.
Room temperature ferromagnetic n-type semiconductor in (In1−xFex)2O3−σJun He, Shifa Xu, Young K. Yoo et al.|Applied Physics Letters|2005 The thin film synthesis and characterization of room temperature ferromagnetic semiconductor (In1−xFex)2O3−σ are reported. The high thermodynamic solubility, up to 20%, of Fe ions in the In2O3 is demonstrated by a combinatorial phase mapping study where the lattice constant decreases almost linearly as Fe doping concentration increases. Extensive structural, magnetic and magneto-transport including anomalous Hall effect studies on thin film samples consistently point to a source of magnetism within the host lattice rather than from an impurity phase.
Combinatorial synthesis and high throughput evaluation of ferroelectric/dielectric thin-film libraries for microwave applicationsHuibin Chang, Chunxiao Gao, Ichiro Takeuchi et al.|Applied Physics Letters|1998 A library of 256 differently doped thin films of (BaxSr1−x)TiO3 (where 0.5<x<1.0) was generated on a 1 in.×1 in. LaAlO3 substrate using multistep thin-film deposition techniques together with a quaternary masking strategy. Appropriate postannealing processing afforded high-quality epitaxial thin films. The microwave properties, i.e., dielectric constant and loss tangent, of samples in the library were characterized with a scanning-tip microwave near-field microscope at 1 GHz, and the results were found to be consistent with measurements made with interdigital electrodes. Specific dopants were found to significantly affect the dielectric constant and tangent loss. Tungsten, in particular, reduces the tangent loss.
Bulk synthesis and high-temperature ferromagnetism of (In1−xFex)2O3−σ with Cu co-dopingYoung K. Yoo, Qizhen Xue, Hyung‐Chul Lee et al.|Applied Physics Letters|2005 The synthesis and magnetic properties of (In1−xFex)2O3−σ bulk ceramics with Cu co-doping are reported. Magnetic Fe ions are found to have high thermodynamic solubility (up to 20%) in the In2O3 host compound. The lattice constant decreases almost linearly as Fe doping concentration increases indicating the incorporation of Fe ions into the host lattice. The samples with high Fe concentration annealed under Ar reduced atmosphere were found to be ferromagnetic, and the Curie temperature is around 750K. The extensive structural and magnetic studies rule out the possibility that the observed magnetism is derived from magnetic impurity phases.
Solution‐phase synthesis of luminescent materials librariesXiaodong Sun, Kai‐An Wang, Young K. Yoo et al.|Advanced Materials|1997 The application of combinatorial methods to the synthesis and characterization of novel materials is described for the case of solution‐phase synthesis of phosphors based on rare‐earth‐activated refractory metal oxides. A scanning multiinkjet system is shown to be suitable for the fabrication of a liberry such as (La m Gd 1‐ m )‐Al n O x :Eu , the photoluminescence image of part of which is shown in the Figure. magnified image