The dramatic increases in ionic conductivity in Gd2(Ti1-xZrx)2O7 solid solution are related to disordering on the cation and anion lattices. Disordering in Gd2(Ti1-xZrx)2O7 was characterized using x-ray photoelectron spectroscopy (XPS). As Zr substitutes for Ti in Gd2Ti2O7 to form Gd2(Ti1-xZrx)2O7 (0.25 < x < or =0.75), the corresponding O 1s XPS spectrum merges into a single symmetric peak. This confirms that the cation antisite disorder occurs simultaneously with anion disorder. Furthermore, the O 1s XPS spectrum of Gd2Zr2O7 experimentally suggests the formation of a split vacancy.

The body-centered-cubic (bcc) phase of Ni, which does not exist in nature, has been achieved as a thin film on GaAs(001) at 170 K via molecular beam epitaxy. The bcc Ni is ferromagnetic with a Curie temperature of 456 K and possesses a magnetic moment of 0.52+/-0.08 micro(B)/atom. The cubic magnetocrystalline anisotropy of bcc Ni is determined to be +4.0x10(5) ergs x cm(-3), as opposed to -5.7x10(4) ergs x cm(-3) for the naturally occurring face-centered-cubic (fcc) Ni. This sharp contrast in the magnetic anisotropy is attributed to the different electronic band structures between bcc Ni and fcc Ni, which are determined using angle-resolved photoemission with synchrotron radiation.

Wire-like SnO 2 is fabricated by the wet chemical method. X-ray diffraction measurements show that the obtained samples have rutile-type structure. Electron transmission microscopy experiments illustrate that the wire-like SnO 2 ranged from 10 to 50 nm in width and several microns (µm) in length. The high-resolution TEM indicates that SnO 2 wires are single crystals. The possible growth mechanism is proposed, and it is found that polyethylene glycol plays an important role in obtaining the wire-like and nano-rods morphology of SnO 2 . The band gap is determined to be 3.56 eV. Two photoluminescence peaks located at 389 and 470 nm are observed. Our fabrication method promises a simple way of synthesizing wire-like SnO 2 at a low temperature of 350 • C.

Tetragonal Sn nanoparticles of ∼15 nm diameter are produced in Al 2 O 3 by direct Sn implantation at room temperature. After thermal annealing at 1000 • C in oxygen, the implantation-induced amorphous region recrystallized and the Sn nanoparticles turned into SnO 2 nanoparticles with an average diameter of ∼30 nm as revealed by transmission electron microscopy. While no absorption and photoluminescence (PL) are observed from the metallic Sn nanoparticles, SnO 2 nanoparticles exhibit an absorption edge at ∼280 nm and three emission bands at 410 nm, 520 nm and 700 nm, respectively. In addition to the previously reported blue and green emission from SnO 2 nanostructures, a red PL band was observed due to the unique surface state of SnO 2 nanoparticles embedded in Al 2 O 3 substrate fabricated by ion implantation.

H + and He + were implanted into single crystals in different orders (H + first or He + first). Subsequently, the samples were annealed at different temperatures from 200 • C to 450 • C for 1 h. Cross sectional transmission electron microscopy, Rutherford backscattering spectrometry and channelling, elastic recoil detection were employed to characterize the defects and the distribution of H and He in the samples. Furthermore, the positron traps introduced by ion implantation and annealing were characterized by slow positron annihilation spectroscopy. Both orders in the coimplantation of H and He have the ability to decreases the total implantation dose after annealing. No bubbles or voids but cracks and platelets, were observed by cross sectional transmission electron microscopy. The different implantation orders affect the density of interstitial atoms and positron traps.