nescence changes from blue to yellow after grinding. Like other such compounds, its original lumi-nescent state is restored upon dissolution and recrystallization, and this process could be repeated for 20 cycles without any decrease in luminescence. Structural and spectroscopic studies indicate that the long-lived blue emission in the crystal is intramolecular in origin and phos-phorescent (a localized intraligand π-π* transition), whereas the yellow emission appears to arise from an amorphous phase characterized by aurophilic interactions: intermolecular interactions between gold atoms.-PDS

Abstract:We have developed a one-pot ring-closing metathesis (RCM)/oxidation methodology to yield various 2-quinolines from 2-vinyl-N-allylaniline derivatives. This is a first example of an oxidation involving methylene (CH 2 ) groups with modified Grubbs-type ruthenium complexes. Hence, this adds an example of a non-methathesis reaction using a ruthenium carbene catalyst.

Synthesis, properties, and catalytic applications of a caged trialkylphosphine ligand with Me 3 P-like steric and electronic characters, 4-phenyl-1-phospha-4-silabicyclo[2.2.2]octane (Ph-SMAP), are reported. Given a phenyl group at the silicon atom, the Ph-SMAP ligand displayed nonvolatility with retention of Me 3 P-like steric and electronic properties. The new ligand is air-stable, crystalline, and easy to handle. Single-crystal X-ray diffraction analyses of Ph-SMAP and its coordination compounds such as borane, rhodium(I), and Pt(II) complexes revealed a rigid, linear structural feature of the Ph-SMAP framework. DFT calculations [B3LYP/6-31G(d,p)] indicated that the electron-donating ability of Ph-SMAP is slightly stronger than that of Me 3 P and that replacement of Si atom of Ph-SMAP with a carbon atom drastically decreases the donor power. The Ph-SMAP ligand markedly accelerated the rhodium-catalyzed hydrosilylation and hydrogenation of ketones as compared with the effect of conventional phosphine ligands such as Me 3 P, Bu 3 P, (t-Bu) 3 P, and PPh 3 , when it was used in combination with [{RhCl(C 2 H 4 ) 2 } 2 ] and [Rh(OMe)(cod)], respectively, with P/Rh ratio of 1:1.

It was shown by Ouyang et al. [Appl. Phys. Lett. 86, 152901 (2005)] that the piezoelectric e31,f coefficient is largest parallel to the spontaneous polarization in tetragonal PbZrxTi1−xO3 (PZT) films. However, the expected piezoelectric data are typically calculated from phenomenological constants derived from data on ceramic PZT. In this work, the dependence of e31,f on c-axis texture fraction, f001, for {001}PZT thin films was measured by growing films with systematically changed f001 using CaF2, MgO, SrTiO3, and Si substrates. An approximately linear increase in e31,f with f001 was observed for compositions up to 43 mol. % Zr, and 100% c-domain properties were extrapolated. It was demonstrated that c-axis PZT films can achieve e31,f exceeding −12 C/m2 for many tetragonal compositions. The energy harvesting figure of merit, e31,f2/εr, for c-axis PZT films surpassed 0.8 C2/m4. This is larger than the figure of merit of gradient-free PZT films grown on Si substrates by a factor of four.

A new orientation control method for depositing (110)-oriented perovskite thin films was demonstrated using a (101)PdO//(111)Pd buffer layer on (100)Si substrates, which is widely used in integrated ferroelectric and dielectric applications. The (101)-oriented PdO was obtained by oxidizing (111)Pd films deposited on a (111)Pt/TiO x /SiO 2 /(100)Si substrate and (110)-oriented perovskites including SrRuO 3 and (Ba 0.5 ,Sr 0.5 )TiO 3 (BST) were obtained on (101)PdO by the RF magnetron sputtering method. Although the BST films deposited at 500 °C were not crystallized, the BST films deposited above 600 °C are fully crystallized and the (110)-orientation is dominant. The (110)-oriented BST thin film showed good dielectric property with high dielectric constant (>600) at 0 kV/cm and high tunability (>50% at +200 kV/cm). Comparing this dielectric property with those of other oriented BST films, both the dielectric constant and the tunability tend to decrease in the order of (111)-, (100)-, and (110)-preferred orientations.

Ultrahigh strain and piezoelectric behavior in relaxor based ferroelectric single crystals Journal of Applied Physics 82, 1804 (1997) Lead zirconate titanate (PZT) film with polar axis orientation was grown on a SUS 316L stainless steel substrate with the help of a Ca 2 Nb 3 O 10 nanosheet (ns-CN) layer that had a pseudo-perovskite-type crystal structure. The ns-CN buffer layer was supported on a platinized SUS 316L (Pt/SUS) substrate, followed by chemical solution deposition (CSD) of the PZT films with tetragonal symmetry (Zr/Ti =40/60). The PZT films consisting of c-domain, with [001]-axis orientation of the perovskite unit cell, were deposited on the ns-CN/Pt/SUS substrate owing to (i) epitaxial lattice matching between the unit cell of PZT and substrate surface and (ii) in-plane thermal stress applied to the PZT film during cooling-down step of CSD procedure. The c-domain-oriented PZT film on ns-CN/Pt/SUS substrate exhibited enhanced remanent polarization of approximately 52 µC/cm 2 and lowered dielectric permittivity of approximately 230, which are superior to those of conventional PZT films with random crystal orientation and comparable to those of epitaxial PZT films grown on (100)SrRuO 3

A strongly {110}-oriented perovskite-type thin film of tetragonal Pb(Zr0.4Ti0.6)O3 (PZT) was successfully obtained on a (100)Si substrate using a {101}PdO//{111}Pd thin film as a buffer layer. The {101}PdO//{111}Pd thin film buffer layer was obtained by oxidizing {111}Pd after depositing {111}Pd on a {111}Pt/TiOx/SiO2/{100}Si substrate. Using this buffer layer, a {110}c-oriented SrRuO3 (SRO) thin film was deposited by sputtering as a bottom electrode of PZT thin films. Subsequently, the {110}-oriented PZT thin film can be deposited on a (110)cSRO thin film by metal–organic chemical deposition (MOCVD) and its properties can be compared with those of PZT thin films with other orientations of {100} and {111}. Among the {100}, {110}, {111}-oriented PZT films, the {100}-oriented one showed the largest remnant polarization, which is in good agreement with those of the PZTs epitaxially grown in the 〈100〉, 〈110〉, and 〈111〉 directions. The other properties, i.e., piezoelectricity and dielectric constants, also showed similar anisotropic tendencies, which is in good agreement with the data reported in the epitaxially grown PZTs.

(111¯)/(111)-oriented rhombohedral Pb(Zr0.65Ti0.35)O3 films with different domain fractions were epitaxially grown on various single crystals. The volume fraction of (111)-polar-axis oriented domains in as-deposited films, Vpol.(as-depo.), was controlled by selecting a single crystal substrate with a different thermal expansion coefficient. Applying an electric field, referred to as “poling treatment”, resulted in irreversible non-180° domain switching from the (111¯)-oriented domain (non-polar-axis) to the (111)-oriented domain (polar-axis), which was observed by synchrotron X-ray diffraction. Remanent polarization (Pr) values were higher than those estimated using the proportional relationship with Vpol.(as-depo.). However, the experimental Pr values were in good agreement with the values estimated using the volume fraction of (111)-oriented domains after applying the poling treatment. In rhombohedral Pb(Zr0.65Ti0.35)O3 films, 30%−50% of the (111¯)-oriented domains switched irreversibly to (111)-oriented domains as a result of the poling treatment. The present results show that the domain structures of films may change dramatically after the poling process, and both before and after the poling state should be characterized in order to interpret polarization and piezoelectric behaviors. This study helps to clarify the ferroelectric and piezoelectric properties of Pb(Zr, Ti)O3 films after poling treatment.