The Zero‐Field Splitting of the Mo<sup>3+</sup> Ground State in Yttrium‐Aluminium Garnet

An overview of recognized structural defects, impurities and related trapping levels and their role in the scintillation mechanism is provided and discussed in single crystal materials belonging to tungstate, Ce‐ or Pr‐doped aluminum perovskite, garnet and finally to Ce‐doped silicate scintillators. New achievements and open problems in deeper understanding of electron and hole self‐trapping phenomena and of the nature of defects in the crystal structure and their ability to localize migrating charge carriers are indicated. Fast optical ceramics and nanocomposite materials are pointed out as possible future advanced scintillators. Such novel technologies can in principle explore materials which are not available in the bulk single crystal form, but their figure‐of‐merit is dramatically dependent on the surface‐interface defect states and related trapping and nonradiative recombination phenomena. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Complex oxide scintillators: Material defects and scintillation performance

Nikl¹,

Laguta

Vedda

2008

Physica Status Solidi (b)

198

106

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The zero‐field splitting of the Mo³⁺ ground state in corundum

Баран

Mirzakhanyan

Sharoyan

et al. 1979

Physica Status Solidi (b)

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For the first time the ESR of Mo3+ ions in u-A1203 single crystals was investigated in /1/ at the frequency u = 9.25 GHz. From the analysis of ESR spectra followed that the trivalent Mo3+ ions with S = 3/2 isomorphously replace the A13+ions. The corundum crystalline field splits the fourfold degenerate ground state A2 of Mo m two Kramers doublets. However, only the intradoublet transition -1/2 e , +1/2 was observed in the X-band, because of the large zero-field splitting (ZFS) between the doublets. It was also shown that the ESR spectrum of Mo3+ is well described by the axially symmetrical spin-Hamiltonian 4 3 + .where S = 3/2, I = 5/2, the z-axis is parallel to the electric field axis C3. In the same paper a method of determining a l a r g e ZFSvalue 12DI at a single low frequency was proposed. However, the accuracy of measurements of angles and magnetic fields usually does not allow a sufficiently accurate determination of 12DI by this method. 3+ in For precise measurements of ZFS between Kramers doublets of Mo corundum we have undertaken a direct search of interdoublet transitions using the millimeter range ESR spectrometer described in /2/. The samples of dimensions 3x7~10 mm were placed inside the 8 mm waveguide cooled by liquid nitrogen. The concentration of Mo3+ ions in the specimens w a s about 0.001 %. The absorption lines corresponding to the electronic transitions +1/2 e , 9 / 2 were found near 165 GHz. The intensities of ESR lines obtained in different 1) Ashtarak-2, USSR.

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ESR and NMR Study of Mixed Yttrium–Lutetium–Aluminum Garnets

Asatryan

Petrosian

Sharoyan

et al. 1980

Physica Status Solidi (b)

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ESR of Mo3+ ions and NMR of 27Al nuclei is investigated in mixed single crystals of yttrium-lutetium-aluminum garnets (Y1-zL~z)3A15012, where 0 5 xs 1. Several new centres of Mo3+ and 27Al compared with Y,Al,O,, and Lu3A150,, single crystals are revealed associated with symmetry and crystalline field parameter changes a t isomorphous substitution of Y3+ ions in therare-earth sublattice of the garnet by those of Lu3+. Symmetry, nearest coordination, and parameters of spin-Hamiltonians are estimated concerning all of M03+ and 27Al centres in (Y1-zLu,),Al,O1, at6~a p y x c e~ pf€n HOBblX, no CpaBHeHtiIo C Y3AI,01, II Lu3A1501,, UeHTPOB M03+ ti 27A1, 06yCJIOBJEHHbIX ti3MeHeHHFIMH CtiMMeTpMti ti IlapaMeTpOB HPtiCTaJIJIHYeCKOrO nOJIII npH ti3OMOp@HO~ 3aMeHe Y3+ Ha LU3+ B penK03eMenbHOi nOAPC!lueTK€! rpaHaTOB. YCTaHOBJleHbI CEIMMeTPHH, 6ntimafiluee OKpyWeHEie EI OIIpeHeJleHbl IIapaMeTpbI CnHH-FaMHJlbTOHIIaHOB BCeX UeHTPOB Mo3+ ti 27Al B KpacTannax (Y1-zLuJ3A1501, npti x < 0,15.

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The Zero‐Field Splitting of the Mo³⁺ Ground State in Yttrium‐Aluminium Garnet

Cited by 14 publications

References 2 publications

Complex oxide scintillators: Material defects and scintillation performance

Complex oxide scintillators: Material defects and scintillation performance

The zero‐field splitting of the Mo³⁺ ground state in corundum

ESR and NMR Study of Mixed Yttrium–Lutetium–Aluminum Garnets

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The Zero‐Field Splitting of the Mo3+ Ground State in Yttrium‐Aluminium Garnet

Cited by 14 publications

References 2 publications

Complex oxide scintillators: Material defects and scintillation performance

Complex oxide scintillators: Material defects and scintillation performance

The zero‐field splitting of the Mo3+ ground state in corundum

ESR and NMR Study of Mixed Yttrium–Lutetium–Aluminum Garnets

Contact Info

Product

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The Zero‐Field Splitting of the Mo³⁺ Ground State in Yttrium‐Aluminium Garnet

The zero‐field splitting of the Mo³⁺ ground state in corundum