An electron paramagnetic resonance and magnetically modulated microwave absorption characterization of thermochromic (Ba, Li)-Mn oxides
- 1. Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-360, Coyoacan, DF 04510 (Mexico)
- 2. Departamento de Ciencias de los Materiales, ESFM-IPN, Edificio 9, Av. Instituto Politecnico Nacional S/N, Col. San Pedro Zacatenco, DF 07738 (Mexico)
- 3. Centro de Ciencias de la Materia Condensada, Universidad Nacional Autonoma de Mexico, Apartado Postal 2681, 22800 Ensenada BC (Mexico)
- 4. Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, 04510 Mexico DF (Mexico)
Description
We report electron paramagnetic resonance (EPR) and magnetically modulated microwave absorption spectroscopy (MAMMAS) studies on powdered BaMnO3 and Li2MnO3 in the 77-300 K temperature range. The two oxides showed one single-line EPR spectra at room temperature. For Li2MnO3 the absorption line changed continuously with temperature, and showed a paramagnetic behavior in the whole temperature range. For BaMnO3 an additional signal was observed below ∼196 K; at low temperature (<135 K) the original signal has practically vanished. The changes in the g-factor, peak-to-peak linewidth (ΔH pp) and integrated intensity (I EPR) as a function of temperature are studied. The MAMMAS spectrum for Li2Mn03 showed a monotonic increase with temperature; this result confirmed its paramagnetic behavior. For BaMnO3 the MAMMAS signal exhibited a maximum at T max=139 K, approximately the temperature for the color change
Additional details
Identifiers
- DOI
- 10.1016/j.jmmm.2007.03.064;
- PII
- S0304-8853(07)00402-7;
Publishing Information
- Journal Title
- Journal of Magnetism and Magnetic Materials
- Journal Volume
- 316
- Journal Issue
- 2
- Journal Page Range
- p. e695-e698
- ISSN
- 0304-8853
- CODEN
- JMMMDC
Conference
- Title
- Joint European magnetic symposia
- Dates
- 26-30 Jun 2006
- Place
- San Sebastian (Spain)
INIS
- Country of Publication
- Netherlands
- Country of Input or Organization
- International Atomic Energy Agency (IAEA)
- INIS RN
- 39035540
- Subject category
- S36: MATERIALS SCIENCE;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- ABSORPTION; ABSORPTION SPECTROSCOPY; BARIUM COMPOUNDS; ELECTRON SPIN RESONANCE; LANDE FACTOR; LITHIUM COMPOUNDS; MANGANESE COMPOUNDS; MICROWAVE RADIATION; OXIDES; PARAMAGNETISM; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0065-0273 K; TEMPERATURE RANGE 0273-0400 K
- Descriptors DEC
- ALKALI METAL COMPOUNDS; ALKALINE EARTH METAL COMPOUNDS; CHALCOGENIDES; DIMENSIONLESS NUMBERS; ELECTROMAGNETIC RADIATION; MAGNETIC RESONANCE; MAGNETISM; OXYGEN COMPOUNDS; RADIATIONS; RESONANCE; SORPTION; SPECTROSCOPY; TEMPERATURE RANGE; TRANSITION ELEMENT COMPOUNDS
Optional Information
- Copyright
- Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.