A Deeper Insight into (Lu,Y)AG:Pr Scintillator Crystals

Interior of Czochralski-grown (Lu,Y)AG:Pr crystals has been examined by means of several techniques, such as X-Ray Photoelectron Spectroscopy, X-Ray Diffraction, Time-of-Flight Secondary Ion Mass Spectrometry, and magnetic susceptibility measurements. Additionally, their luminescence has been monitored at various combinations of a double-beam (X-ray/IR) excitation

A deeper insight into (Lu,Y)AG : Pr scintillator crystals

Interior of Czochralski-grown (Lu,Y)AG:Pr crystals has been examined by means of several techniques, such as X-Ray Photoelectron Spectroscopy, X-Ray Diffraction, Time-of-Flight Secondary Ion Mass Spectrometry, and magnetic susceptibility measurements. Additionally, their luminescence has been monitored at various combinations of a double-beam (X-ray/IR) excitation

The investigation of YAlO3-NdAlO3 system, synthesis and characterization

The binary phase diagram of the YAlO3 (YAP) - NdAlO3 (NAP) system was determined by differential thermal analysis (DTA) and X-ray powder diffraction (XRD) measurements. High purity nanocrystalline powders and small single crystals of Y_{1-x}Nd_{x}AlO_3 (0 \leq x \leq 1) have been produced successfully by modified sol-gel (Pechini) and micro-pulling-down methods, respectively. Both end members show high mutual solubility >25% in the solid phase, with a miscibility gap for intermediate compositions. A solid solution with x \approx 0.2 melts azeotropic ca. 20 degrees below pure YAP. Such crystals can be grown from the melt without segregation. The narrow solid/liquid region near the azeotrope point could be measured with a "cycling" DTA measurement technique.Comment: 12 pages, 8 figures, submitted to J. Alloys. Comp

Electron Spin Resonance Spectra of Fe3+\text{}^{3+} Ions in SrLaAlO4\text{}_{4} and SrLaGaO4\text{}_{4} High-Tc\text{}_{c} Substrates

New results concerning paramagnetic defects in SrLaAlO$\text{}_{4}$ and SrLaGaO$\text{}_{4}$ high-T$\text{}_{c}$ substrates connected with unavoidable impurity Fe$\text{}^{3+}$ are reported. The identification was checked by measuring the spectra in SrLaAlO$\text{}_{4}$ crystals intentionally doped with 0.5 at.% Fe. Angular dependences of three lines were distinguished at X-band frequency in the temperature range from 4 K to 300 K. We attribute these lines to the transitions inside the doublets ±1/2, and "forbidden" doublets ±3/2, ±5/2, respectively. By diagonalization of spin-Hamiltonian, parameters |D| > 1.2 cm$\text{}^{-1}$, |E| ≈ 0.1 cm$\text{}^{-1}$ and g$\text{}_{x}$=g$\text{}_{y}$=g$\text{}_{z}$= 1.987(13) for SrLaAlO$\text{}_{4}$ and SrLaGaO$\text{}_{4}$ were calculated and within the margin of error they were of the same value

Study of SrLaAlO4\text{}_{4} and SrLaGaO4\text{}_{4} Substrate Crystals by Raman Spectroscopy

In this paper the study of SrLaAlO$\text{}_{4}$ and SrLaGaO$\text{}_{4}$ single crystals using the Raman scattering method is presented. The obtained results are discussed in terms of nature of the crystallografic imperfections and point defects which might arise during the crystal growth process

Electron Spin Resonance Study of Thermal Defects in SrLaAlO4\text{}_{4} and SrLaGaO4\text{}_{4} High-Tc\text{}_{c} Substrates

The effect of annealing SrLaAlO$\text{}_{4}$ (SLA) and SrLaGaO$\text{}_{4}$ (SLG) crystals in oxidizing and reducing atmospheres in the temperature range of 950°C-1300°C was investigated. Three kinds of anisotropic defects D$\text{}_{1}$, D$\text{}_{2}$, and E at the temperature range of 4-300 K were found. By diagonalization of orthorhombic spin-Hamiltonian parameters: |D|=0.0541(10) cm$\text{}^{-1}$, |E|=0.0108(10) cm$\text{}^{-1}$, g$\text{}_{∥}$=0.883(5), and g$\text{}_{⊥ }$=1.922(5) for D$\text{}_{1}$ defects for SLG and SLA were calculated and they had the same values within the margin of error

Surface of BiSrCaCuO Single Crystal Observed by Means of Scanning Tunneling Microscope

The topographic images of a Bi$\text{}_{0.7}$Pb$\text{}_{0.3}$SrCaCu$\text{}_{1.8}$O$\text{}_{x}$ single crystal were studied by means of the scanning tunneling microscope. The structure of terraces and steps seen on the surface reflects the crystallographic structure of bulk

Elastooptic Constants of SrLaAlO4\text{}_{4} and SrLaGaO4\text{}_{4} Single Crystals Determined by Brillouin Scattering

In this paper we report the elastooptic constants p$\text{}_{ij}$ of strontium lanthanum aluminate, SrLaAlO$\text{}_{4}$ and strontium lanthanum gallate SrLaGaO$\text{}_{4}$ single crystals, which were determined at room temperature using Brillouin scattering method. In order to investigate the elastooptic constants of SrLaAlO$\text{}_{4}$ and SrLaGaO$\text{}_{4}$ single crystals, a substitution method proposed by Cummins and Schoen, and developed by Nelson and Lax was used. The obtained results are also discussed in terms of the nature defects which might arise in these crystals during growth process

Isovalence Substitutions in Multicomponent Aluminates ABCO4\text{}_{4}

The crystallochemical characteristics of polycrystalline samples, Sr$\text{}_{1-x}$La$\text{}_{x}$AlO$\text{}_{4}$, Sr$\text{}_{1-x}$Νd$\text{}_{x}$ΑlO$\text{}_{4}$ (x = 0.02+0.20) and Sr$\text{}_{1-x}$Bi$\text{}_{x}$NdΑlO$\text{}_{4}$ (x = 0.05 ÷ 0.50) prepared by the oxalate coprecipitation and cryochemical technique have been investigated. The existence limits of single-phase states for pairs of elements Sr-Pb (x < 0.05) and Nd-Bi (x < 0.2) were determined. The microprobe X-ray analysis showed the Bi uniform distribution. The dielectric properties of pure SrLaΑlO$\text{}_{4}$, SrLaGaO$\text{}_{4}$ and partial replacement La → Nd samples were measured. It can be concluded that these compounds are suitable as substrate materials of HTSC thin films