Investigation of structural states and oxidation processesin Li0.5Fe2.5O42d using TG analysis; Journal of Thermal Analysis and Calorimetry; Vol. 108, iss. 3

Bibliographic Details
Parent link:	Journal of Thermal Analysis and Calorimetry Vol. 108, iss. 3.— 2012.— [P. 1603-1609]
Corporate Authors:	Национальный исследовательский Томский политехнический университет (ТПУ) Институт неразрушающего контроля (ИНК) Проблемная научно-исследовательская лаборатория электроники, диэлектриков и полупроводников (ПНИЛ ЭДиП), Национальный исследовательский Томский политехнический университет (ТПУ) Институт неразрушающего контроля (ИНК) Кафедра физических методов и приборов контроля качества (ФМПК)
Other Authors:	Surzhikov A. P. Anatoly Petrovich, Frangulyan (Franguljyan) Т. S. Tamara Semenovna, Vasiljev I. P. Ivan Petrovich, Lysenko E. N. Elena Nikolaevna, Gyngazov (Ghyngazov) S. A. Sergey Anatolievich
Summary:	Title screen Using the methods of X-ray phase and DSC analyses, a correlation is established between ordering/ disordering of the structure of lithium pentaferrite (LPF-Li0.5Fe2.5O4-d) and its nonstoichiometry with respect to oxygen. Ferrite specimens with a reduced content of oxygen were prepared by thermal annealing in vacuum (P = 2 9 10-4 mmHg). It is shown that this treatment results in oxygen nonstoichiometry and causes a transition of LPF into a state with random distribution of cations in the crystal lattice. Using nonisothermal thermogravimetry (TG), the kinetic dependences of oxygen absorption by the aniondeficient LPF are investigated within the temperature interval T = (350-640) _C in the course of its oxidation annealing in air. The kinetic experiment data are processed with the Netzsch Thermokinetics software. The oxidation rate constants, the effective coefficients, and the activation energy of oxygen diffusion in the material under study are derived. Their values are in a satisfactory agreement with those earlier obtained for the lithium-titanium ferrite ceramic material of the following composition: Li0.649 Fe1.598Ti0.5Zn0.2Mn0.051O4-d. The effective activation energy of oxygen diffusion in LPF calculated within the temperature interval T = (350-640) _C is found to be Ed = 1.88 eV. In its value, it is close to the activation energy of oxygen diffusion along grain-boundaries in the lithium-titanium ferrite ceramic material. Режим доступа: по договору с организацией-держателем ресурса
Language:	English
Published:	2012
Subjects:	электронный ресурс труды учёных ТПУ lithium pentaferrite oxygen nonstoichiometry energy diffusion
Online Access:	http://dx.doi.org/10.1007/s10973-011-1734-z
Format:	Electronic Book Chapter
KOHA link:	https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=646313