Spectral response of CdS with Ag,Cu, and in impurities

High-resistance (dark 10⁸ · cm) photosensitive CdS samples (light 10²–10³ · cm at saturation) were obtained from low-resistance ( 0.1 · cm) nonphotosensitive CdS single crystals by thermal diffusion of Cu, Ag, and In in vacuum at 2 · 10^–5 torr. The spectral response of impurity and pure high-resistance photosensitive single-crystal CdS samples was studied in the wavelength range from 0.35 to 3. The short-wave and long-wave limits of the spectral curves, the wavelength range of maximum photoconductivity and the forbidden band width, the depth of impurity levels, the upper edge of the impurity band, and the depth of maximum-density activation centers have been determined from the spectral curves. The results are discussed and compared with published data.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 117–121, June, 1972.     

Magnetic impurities in pure gold

Measurements of the resistivity and thermopower of pure gold samples show that it is possible to identify and determine the concentration of magnetic impurities below 1 ppm.     

Magnetic response of nonmagnetic impurities in cuprates

A theory of the local magnetic response of a nonmagnetic impurity in a doped antiferromagnet, as relevant to the normal-state in cuprates, is presented. It is based on the assumption of the overdamped collective mode in the bulk system and on the evidence that equal-time spin correlations are only weakly renormalized in the vicinity of the impurity. The theory relates the Kondo-like behavior of the local susceptibility to the anomalous temperature dependence of the bulk magnetic susceptibility.     

Identification of Cu and Ag acceptors in CdTe

We report here on the identification of the two dominant acceptor levels in high purity p type CdTe, with Cu and Ag on Cd site. This identification is based on back doping experiments coupled with electrical measurements and photoluminescence studies. Cu and Ag can form easily complex centers when a supersaturation is achieved. The way of obtained good doping without complexation, is explained. The principal bound exciton lines are at 1,5896 eV (Cu) and at 1,5885 eV (Ag). The precise hole binding energies obtained from optical data are E_A (Cu) = 146 meV and E_A (Ag) = 108 meV.     

Magnetic characteristics of ferromagnets containing impurities

Magnetization distribution is studied in the vicinity of defects in a single axis ferromagnet. The correction to the static magnetic susceptibility due to defects is significant for small magnetocrystalline anisotropy.     

Grain Boundary Motion during Ag and Cu Grain Boundary Diffusion in Cu Polycrystals

Grain boundary (GB) motion in high-purity Cu material (5N8 and 5N Cu) is investigated using the results of radiotracer GB diffusion measurements with tracers exhibiting fundamental differences in the solute-matrix atom interactions. The results on GB solute diffusion of Ag (revealing a miscibility gap in the Ag-Cu phase diagram) and Au (forming intermetallic compounds with Cu) in Cu and on Cu self-diffusion are analyzed.The initial parts of the Ag and Cu penetration profiles turned out to be substantially curved. The profile curvature is explained via the effect of GB motion during ^110m Ag and ⁶⁴Cu GB penetration. The activation enthalpies of GB motion in these two independent measurements occurred to be very close, 95 and 103 kJ/mol, respectively. Moreover, these values turn out to be close, but still somewhat larger than the activation enthalpy of Cu GB self-diffusion in Cu material of the same very high purity, Q ^Cu _gb = 72 kJ/mol. Although tracer diffusion measurements of Au GB diffusion in Cu yielded only limited information on GB motion, the absolute values of GB velocities are consistent with those calculated from the Ag and Cu GB diffusion data.     

用FAAS法测定铅电解液中的铜和银

本文采用原子吸收法测定铅电争液中的Ｃｕ和Ａｇ。Ｃｕ的相对标准偏差为５．１％,Ａｇ的相对标准偏差为４．２％,方法简单,回收率在９６．７％－１０６．７％之间。     

Excited states of Ag and Cu acceptors in CdTe

We report on resonantly excited luminescence (REL) at 1.8 K and infrared absorption (IRA) between 6–12 K of CdTe doped with Ag and Cu impurities. The luminescence was excited with a tunable dye laser. Two hole transitions up to $\text{6}\text{S}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ state have been observed, the bound exciton lines have been identified. $\text{2}\text{P}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$ states have been observed in IRA measurements. The binding energies as deduced from REL experiments are 107.5 meV for Ag and 146 meV for Cu. The fitted values of the valence band parameters are Ro = 27 ± 3 meV μ = 0.73 ± 0.03 and δ = 0.12 ± 0.01.     

Virtual bound states of Pd in Cu,Ag and Au and of Pt in Ag

The positions and widths of the virtual bound states of 5 and 10% Pd in Cu, Ag and Au and of 5 and 10% Pt in Ag have been measured by XPS. The spin—orbit splitting of the Pt state in Ag is reduced from the theoretical value, but comparable to the spectroscopic atomic value. The host lattice d-band structure is perturbed in the alloys.