Large Two-Magnon Raman Hysteresis Observed in a Magnetically Uncompensated Hematite Coating across the Morin Transition
| Autor: | Jesús López-Sánchez, Adolfo del Campo, Sara Román-Sánchez, Óscar Rodríguez de la Fuente, Noemí Carmona, Aída Serrano |
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| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Coatings; Volume 12; Issue 4; Pages: 540 E-Prints Complutense. Archivo Institucional de la UCM Universidad Europea (UEM) |
| ISSN: | 2079-6412 |
| DOI: | 10.3390/coatings12040540 |
| Popis: | A temperature-dependent Raman experiment between 80 and 600 K was performed in a nanoparticulated coating of single-phase hematite grown on a silica substrate. In that range, a thermal Raman shift hysteresis was identified in the vibrational modes that accompanies the Morin transition, observing large effects in the two-magnon Raman frequency position and in its relative intensity. Interestingly, no decrease in coercivity occurs when the hematite crosses the Morin transition below 230 K. The spin-flop processes produced in the coating leads to a strong decompensation of the surface spins, generating a ferromagnetic component over the whole temperature range studied. Such unusual effects might be promoted by a certain degree of structural disorder and the stresses produced by the nanoparticulation growth approach of the hematite coating. As a result, a high stability of the two-magnon excitation is obtained over a wide temperature range and considerable advances are made for the development of spintronic devices based on semiconductor antiferromagnetic materials. |
| Databáze: | OpenAIRE |
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