| Autor: |
Ardelean, I., Cozar, O., Craciun, C., Cefan, C. |
| Předmět: |
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| Zdroj: |
International Journal of Modern Physics B: Condensed Matter Physics; Statistical Physics; Applied Physics; 7/30/2002, Vol. 16 Issue 19, p2807, 7p |
| Abstrakt: |
Electron paramagnetic resonance (EPR) and magnetic susceptibility studies on xV[sub 2]O[sub 5]· (100 - x)[2B[sub 2]O[sub 3] · SrO] glasses with 0 ≤ x ≤ 30 mol% were performed. The covalence degree of vanadium bonds was estimated according to the LCAO-MO model. The EPR data show the presence of V[sup 4+] ions in a square-pyramidal coordination (C[sub 4v]). The experimental EPR spectra are simulated assuming a superposition of two signals, one with hyperfine structure (HFS) typical for isolated ions and the other one consists of a broad line without HFS characteristic for clustered ions. These results are consistent with the magnetic data which indicate that for x ≥ 5 mol% V[sub 2]O[sub 5] the temperature dependence of the reciprocal magnetic susceptibility is described by a Curie-Weiss type law with negative paramagnetic Curie temperature. The magnetic data also allow the estimation of N[sub V4+]/N[sub V[sub total]] ratio. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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