Growth,Compositions, and Mechanical Characteristics of Sodium–Gadolinium Molybdate Single Crystals

Crystallography Reports - A concentration series of sodium–gadolinium molybdate single crystals have been grown by the Czochralski method from melts of stoichiometric and some...     

Rare-earth scandium garnets as an object of crystallization

The paper discusses the features of RESG which influence the crystal growth. RESG are nonstoichiometric compounds with complex scandium isomorphism which results in substantial variations of the crystallized composition. The presence of chrormuim ions in RESG strongly increases the absorption capability of the medium and leads to the rise of interface instability during the growth. The principle differences between ScGa- and ScAl-garnets concerning crystallization features are considered.     

Status of the High-Voltage Electron-Cooling System of the NICA Collider

Physics of Particles and Nuclei Letters - In order to achieve the design luminosity in the NICA collider, it is planned to equip it with both stochastic and electron cooling. The electron-cooling...     

Simulation of Simple and Complex Gadolinium Molybdates by the Interatomic Potential Method

Crystals of ferroelectric?ferroelastic gadolinium molybdate Gd₂(MoO₄)₃, calcium molybdate CaMoO₄, and double sodium?gadolinium molybdates of stoichiometric (Na_1/2Gd_1/2MoO₄) and cationdeficient (Na_2/7Gd_4/7MoO₄) compositions, which are used to design solid-state lasers, phosphors, and white LEDs, have been simulated by the interatomic potential method. Their structural, mechanical, and thermodynamic properties are calculated using a unified system of interatomic potentials and effective ion charges, which demonstrated transferability and made it possible not only to describe the existing experimental data but also to predict some important physical and thermodynamic properties of molybdate crystals. The influence of the deviation from stoichiometry and partial ordering of cations on sites in nonstoichiometric crystals on the properties and local structure of sodium?gadolinium molybdates is discussed.     

Tunable room-temperature cw laser action in Cr3+: GdScGa-Garnet

We report for the first time on tunable room temperature cw laser action of a transition metal laser material. In Cr³⁺:GdScGa-garnet crystals almost the total fluorescence is channelled into the broad band⁴ T ₂→⁴ A ₂ transition. The fluorescence lifetime is τ=120 μs. Laser pumping in the blue-green and yellow-red spectral range yields pump thresholds around 250 mW and slope efficiencies up to 11%. The wavelength of the free running Cr³⁺ laser is centered at 777 nm.     

Relaxation of the dynamic system induced by the parametric modulation of its hamiltonian by the functional of the Markov process

Institute of Chemical Kinetics and Combustion, Siberian Branch, Academy of Sciences of the USSR. Translated from Izvestiya Vysshikh Zavedenii, Radiofizika, Vol. 33, No. 6, pp. 666–672, June, 1990.     

Observation of electric quadrupole spin resonance of Ho<Superscript>3+</Superscript> impurity ions in synthetic forsterite

The anomalous dependence of the electron paramagnetic resonance (EPR) line shape on the microwave power in the resonator has been found when studying the continuous-wave EPR spectra of impurity holmium ions in synthetic forsterite on an ELEXSYS E 580 EPR spectrometer. The power-threshold transition from the conventional lines being the derivatives of the spectral line contours to the spectral line contours themselves has been observed as the power increased. The properties of the anomalous EPR lines are qualitatively explained assuming that the resonance electric quadrupole transitions take place between the electron spin levels.     

EPR Study of the Vanadium Ions in Mg2SiO4 Crystal

Vanadium-doped forsterite crystal has been studied with X-band electron paramagnetic resonance (EPR) spectroscopy. The sample was grown by the Czochralski technique in an argon atmosphere with 2 vol% of hydrogen. The EPR spectrum of the sample at T = 15 K is predominantly represented by the V⁴⁺ ion signals that possess a characteristic eight-line hyperfine structure and are observed close to g = 2. The observation of the two magnetically nonequivalent centers in the angular dependence in the (ab) crystal plane and one center in the (ac) and (bc) planes, combined with the published optical spectroscopy data, unambiguously show that the V⁴⁺ ions are located at the silicon lattice site. Principal values of the hyperfine A and g-tensor and magnetic axes orientations of the V⁴⁺ centers have been determined. The orientation disorder of the V⁴⁺ centers has been found around the crystalline c axis but not in the (ab) crystal plane. The angular variation of the hyperfine component linewidth is described best with a disorder range of ±3.0°.