Results 121 to 130 of about 454 (154)

The Madelung Function of Elpasolites

Zeitschrift für Naturforschung B, 2000
Abstract Madelung Energy, Coulomb Interaction, Elpasolite For binary ionic compounds the Madelung energy can be calculated using the Madelung constant, the ionic charges and the next neighbour distance of the ions only. For ternary and higher systems the well-known standard formula cannot be applied, because the ionic charges and ...
Veit Marx, Bernd Hundhammer
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Specific heat of the elpasolite Pb2MgWO6

Physics of the Solid State, 1999
The specific heat of Pb2MgWO6 has been measured in the temperature interval 83–370 K. An anomaly in the specific heat associated with the phase transition at T 0=312.8K has been discovered. The thermodynamic parameters of the structural phase transition Fm3m-Pmcn have been determined.
I. N. Flërov, M. V. Gorev, Ph. Sciau
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Thermodynamic properties of (NH4)2KGaF6 elpasolite

Physics of the Solid State, 2001
The heat capacity of (NH4)2KGaF6 elpasolite is measured in the temperature range from 80 to 350 K. A sequence of three phase transitions at T 1=288.5 K, T 2=250 K, and T 3=244.5 K is revealed, and the thermodynamic characteristics of these transitions are determined.
I. N. Flerov, M. V. Gorev, M. L. Afanas’ev, T. V. Ushakova   +3 more
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Cooperative processes in Cs2NaYbF6 elpasolite crystals

Journal of Luminescence, 2014
Abstract Spectroscopic and luminescent properties of Yb3+-doped Cs2NaYF6 and stoichiometric Cs2NaYbF6 crystals are studied in the infrared and visible spectral regions. The stoichiometric Cs2NaYbF6 compound demonstrates a visible emission when excited by the laser radiation with the wavelength of about 1 μm.
D.S. Pytalev, A. Jaffres, P. Aschehoug, P.A. Ryabochkina, A.V. Malov, N.M. Khaidukov, M.N. Popova   +6 more
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Phase transitions in elpasolites (ordered perovskites)

Materials Science and Engineering: R: Reports, 1998
Abstract Many compounds with general chemical formula A 2 BB′X 6 and with tolerance factor value ...
I.N. Flerov, M.V. Gorev, K.S. Aleksandrov, A. Tressaud, J. Grannec, M. Couzi   +5 more
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Crystal structure of Rb-elpasolite Rb2NaAlF6

Crystallography Reports, 2013
Single crystals of Rb2NaAlF6, the Rb analogue of the mineral elpasolite, are obtained in the NaF-Rb2CO3-Al2O3-Rb3PO4-H2O system under hydrothermal conditions, and their structure is determined by X-ray diffraction (R = 0.0188): a = 8.3087(1) A, space group \(Fm\bar 3m\), Z = 4, and ρcalcd = 3.88 g/cm3. The hypothesis that Rb elpasolite exists in nature
O. V. Yakubovich, G. V. Kiryukhina, O. V. Dimitrova   +2 more
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Pulse Shape Discrimination With Selected Elpasolite Crystals

IEEE Transactions on Nuclear Science, 2012
In recent years, a number of materials from the elpasolite crystal family have been under development for either or both gamma ray and neutron detection. The scintillators show good energy resolution and thermal neutron detection efficiency. The latter is achieved due to the fact, that the selected compositions contain Li-6 ions.
Jarek Glodo, Rastgo Hawrami, Edgar van Loef, Urmila Shirwadkar, Kanai S. Shah   +4 more
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Two-photon absorption spectrum of gadolinium elpasolite

Chemical Physics Letters, 1991
Abstract Observations on parity-allowed direct two-photon transitions within the 4f 7 configuration of Gd 3+ ion in a centrosymmetric Cl − environment are presented. The observed spectrum allows identification of the 00 bands and determination of crystal field splittings.
Liudmila Kundu, Asok K. Banerjee, Mihir Chowdhury   +2 more
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Development of an elpasolite planetary science instrument

2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop (NSS/MIC/RTSD), 2016
Planetary gamma-ray and neutron spectroscopy from orbiting spacecraft has become a standard technique to measure distinctive composition and abundance signatures for key elements relevant to planetary structure and evolution. Previous instrumentation that has led to the discovery of the concentration of many elements including hydrogen (a strong ...
Suzanne F. Nowicki, Laura C. Stonehill, Daniel D. S. Coupland, Katherine E. Mesick   +3 more
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Thermochemical investigations on chloro-elpasolites of lanthanum

Thermochimica Acta, 1994
Abstract Elpasolites A2BLaCl6 with alkali metal chlorides (LiCl excepted) have been prepared from the melts. They are Cs2RbLaCl6 (dimorphous), Cs2KLaCl6 (trimorphous), Cs2NaLaCl6 and Rb2KLaCl6 which is stable only at T⩾748 K. According to X-ray diffraction measurements of crystal powders all compounds have modifications with the cubic elpasolite ...
G. Friedrich, H. Fink, H.J. Seifert
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