Effect of the paramagnetic to spin-glass phase transition on the fundamental absorption edge of MnIn2Se4 magnetic semiconducting compound



Document title: Effect of the paramagnetic to spin-glass phase transition on the fundamental absorption edge of MnIn2Se4 magnetic semiconducting compound
Journal: Revista mexicana de física
Database: PERIÓDICA
System number: 000429657
ISSN: 0035-001X
Authors: 1
2
1
1
Institutions: 1Universidad de Los Andes, Facultad de Ciencias, Mérida. Venezuela
2Universidad de Zaragoza, Instituto de Nanociencia de Aragón, Zaragoza. España
Year:
Season: Ene-Feb
Volumen: 65
Number: 1
Country: México
Language: Inglés
Document type: Artículo
Approach: Analítico, teórico
English abstract The temperature dependence of the indirect and direct fundamental band gaps of the layered compound MnIn2Se4, that crystallizes in a rhombohedral defect structure with space group R 3 - m D 3 d 5, was studied by optical absorption spectra. The data were analyzed in terms of current theoretical models that take into account the contribution of antiferromagnetic exchange interaction between spins to the shift of the energy gap E G with T in the vicinity of the critical paramagnetic to spin-glass phase transition. It was established that short- and long-range effect spin correlations dominate the contribution to this shift in the critical region below about 20 K, near the spin-glass freezing temperature T f , and noncritical one, between about 70 and 160 K, far from T f , respectively. An intermediate temperature region, compatible with the behaviour expected for a cluster-glass transition where a gradual freezing of the magnetic moments occurs, was also observed
Disciplines: Física y astronomía
Keyword: Física de materia condensada,
Semiconductores,
Estructura de banda electrónica,
Intercambio y superintercambio,
Efectos de orden-desorden
Keyword: Condensed matter physics,
Semiconductors,
Electronic band structure,
Exchange and superexchange,
Order-disorder effects
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