Electrophysical properties of non-stoichiometric lithium-iron magnesium-substituted spinels

Samples having the chemical formula Li_0.5 Fe_{2.5 – x} Mg_xO₄ (0 ≤ x ≤ 1) were prepared by the standard ceramic method. The parts of the dielectric constant υ', υ'' and A.C. conductivity σ(ω) are measured at different frequencies from 10^{– 2} to 10⁵ Hz in the room temperature and different cooling velocity, and then the dielectric loss tangent tg Δ was calculated. The sample with x = 0.1 what was cooled quickly showed the greatest values of σ₀ as compared with the other samples. The effect of Mg^{2 +} concentration on the dielectric parameters is discussed according to the Koops model.

Authors:

Gasyuk I. M., Carpathian National University of V. Stefanik, 57, Shevchenko St., Ivano-Frankovsk, 76025

Kaikan L. S., Carpathian National University of V. Stefanik, 57, Shevchenko St., Ivano-Frankovsk, 76025

Ugorchuk V. V., Carpathian National University of V. Stefanik, 57, Shevchenko St., Ivano-Frankovsk, 76025

Grabko T. V., Carpathian National University of V. Stefanik, 57, Shevchenko St., Ivano-Frankovsk, 76025

Literature

1. Малышев А. В., Пешев В. В., Притулов А. М. // Изв. вузов. Физика. 2003. № 7. C. 48–53.
2. El Kony D. // Egypt. J. Solids, 2004. V. 27, № 2. P. 285–297.
3. Koops C. G. // Phys.Rev. 1951. V. 33, № 1. P. 121–124.
4. Гасюк І.М., Будзуляк І.М, Галігузова С. А., Угорчук В. В., Кайкан Л. С. // Наносистеми, наноматеріали, нанотехнології. 2006. Т. 4, вип. 3. C. 613–622.
5. Остафійчук Б. Л., Гасюк І.М., Кайкан Л. С., Депутат Б. Я., Морушко О. В. // Фізика і хімія твердого тіла. 2006. Т. 7, № 2. C. 202–206.
6. Гасюк І.М., Кайкан Л. С., Грабко Т. В. // Фізика і хімія твердого тіла, 2007. Т. 8, № 1. C. 28–34.
7. Samy A. // Egypt. J. Solids. 2006. V. 29, № 1. P. 131–140.
8. Журавлев Г. И. Химия и технология ферритов. Л.: Химия, 1970. 192 с.
9. Abdullah M. N., Yusoff A. N. // J. of Alloys and Compounds. 1996. Vol. 233(1). P. 129–135.
10. Ahmed M. A., Samiha T. Bishay // J. of Physics D: Applied Physics. 2001. Vol. 34. P. 1339–1345.

Journal issue:

2008. Т. 8, № 1,