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Jahn-Teller impurity dependence of the transition· . I 1 tetnper~ture Tcu· criticai exponent and pseudo~JahtiTeller p~tenthd -well splitting in ZoTiF6 • 6H20

De, Dilip Kumar (1987) Jahn-Teller impurity dependence of the transition· . I 1 tetnper~ture Tcu· criticai exponent and pseudo~JahtiTeller p~tenthd -well splitting in ZoTiF6 • 6H20. J.Phys C:Solid State Phys, 20. p. 5911.

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Abstract

The 182.K (::.91.2 °C) trigohal-to-mouoclinic phase transition in ZnTiF6 • 6HP _ sin&Je CI1(Stal has been studied by EPR, for various concentrations of doped Jahn-Teller (JT) , .. - impar4ty Cu2+ ions and also for non-JT impurity NF+ ions. Tbe tr~nsition temperature Td which decreases with increase in impurity concentration, is more strongly affected by the JT impurity. The critical exponent {3 as well as the JT potential well splitting E0 have been determiqd from the temperature variation in EPR signal intensity in the immedi-ate neighbourhood ef Tc1 for the Cu2+ impurity. The critical exponent {3 and E0 are dependent strongly on the JTimpurity concentmtioP For two different concentrations of Cu2+ ions, i.e. : 0.043 wt% and 0.98 wt%, the values of p ,,;e().5 ± 0.05 and 0.12 ± 0.03, respectively, while the values of E0.are 140 ± 15 cm-J -and-97.:!; 1.1 cm-1, respectively. The valN.e of £ 0 for a deuteratcd crystal containing a low Cu2+ conccntrati~s 78 ± 10 cm-1• The dec.rease in E0 with incn:asing Cu2 t c.oncentration fur a hydrated crystal and also with deuteration (for n , low copper concentration) is in qualitative agreement with the corresponding gradual phase . transition observed in these materials

Item Type: Article
Subjects: Q Science > Q Science (General)
Q Science > QC Physics
Divisions: Faculty of Engineering, Science and Mathematics > School of Physics
Depositing User: Mrs Hannah Akinwumi
Date Deposited: 22 Apr 2015 15:18
Last Modified: 22 Apr 2015 15:18
URI: http://eprints.covenantuniversity.edu.ng/id/eprint/5089

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