Search

Your search keyword '"I. M. Fita"' showing total 4 results
Start Over Author "I. M. Fita" Publisher hal ccsd
4 results on '"I. M. Fita"'

1. Exchange bias training effect in phase separated polycrystalline Sm0.1Ca0.7Sr0.2MnO3

Author

A. Wisniewski, I. M. Fita, C. Martin, G. Jung, Roman Puzniak, V. Markovich, G. Gorodetsky, Ben-Gurion University of the Negev (BGU), Polish Academy of Sciences (PAN), Institute of Plasma Physics and Laser Microfusion [Warsaw] (IPPLM), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Magnetism, Phase separation, 02 engineering and technology, 01 natural sciences, Magnetization, Phase (matter), 0103 physical sciences, [CHIM.CRIS]Chemical Sciences/Cristallography, Antiferromagnetism, [CHIM]Chemical Sciences, General Materials Science, 010306 general physics, Condensed matter physics, Magnetic moment, Hysteresis, [CHIM.MATE]Chemical Sciences/Material chemistry, Coercivity, 021001 nanoscience & nanotechnology, Condensed Matter Physics, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Exchange bias, Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology, Néel temperature
Abstract

International audience; Magnetic properties of antiferromagnetic (AFM) electron doped manganite Sm0.1Ca0.7Sr0.2MnO3 have been investigated, focusing mainly on the exchange bias (EB) effect and associated training effect. The studied compound exhibits the ground state with heterogeneous spin configuration, consisting of the C-type antiferromagnetic phase with the Néel temperature TN-C ≈ 120 K, the G-AFM phase with the Néel temperature TN-G ≈ 60 K, and ferromagnetic-like phase with a very weak spontaneous magnetic moment. Measurements of hysteresis loops have shown that the exchange bias field monotonously decreases with increasing temperature and vanishes above 40 K, while the coercivity disappears only above 70 K. The temperature variation of the exchange bias field has been successfully described by an exponential decay form. The stability of EB has been evaluated in the studies of the training effect, which has been discussed in the frame of the spin relaxation model, elucidating the important role of the AFM domain rearrangement at the interface. The complex phase separation and possible contributions from different interfaces between coexisting magnetic phases to the EB effect have also been discussed. © 2016 Elsevier B.V.

Published
2016
Full Text
View/download PDF

2. Exchange bias effect in CaMn0.9Nb0.1O3

Author

Roman Puzniak, C. Martin, G. Gorodetsky, P. Iwanowski, I. M. Fita, Grzegorz Jung, A. Wisniewski, V. Markovich, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Ben-Gurion University of the Negev (BGU), Institute of Physics, Polish Academy of Sciences, Polska Akademia Nauk = Polish Academy of Sciences (PAN), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
02 engineering and technology, 01 natural sciences, 0103 physical sciences, Magnetic properties, [CHIM.CRIS]Chemical Sciences/Cristallography, Antiferromagnetism, [CHIM]Chemical Sciences, General Materials Science, Exponential decay, 010306 general physics, Magnetic materials, Condensed matter physics, Chemistry, Hysteresis, Oxides, [CHIM.MATE]Chemical Sciences/Material chemistry, Coercivity, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Magnetic hysteresis, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Exchange bias, Ferromagnetism, Magnetic structures, Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology, Néel temperature
Abstract

International audience; The exchange bias effect in CaMn0.9Nb0.1O3 has been investigated. It was found that both vertical and horizontal shifts in magnetic hysteresis loop of field cooled sample decrease monotonously with increasing temperature and vanish above 70 K, while the coercivity disappears only above 90 K, upon approaching the Néel temperature. An exponential decay successfully describes variation of the shifts with temperature. The exchange bias phenomenon is in general attributed to low-temperature phase separation into ferromagnetic clusters immersed in the G-type or C-type antiferromagnetic matrix and the resulting appearance of interfaces between coexisting different magnetic phases. Our results indicate that the exchange bias effect in CaMn0.9Nb0.1O3 may be induced, at least partially, by Dzyaloshinsky-Moriya interactions. Measurements of hysteresis loops at various cooling fields from the range -90 < H < 90 kOe show that magnetization at magnetic field H > 20 kOe exhibits a nonlinear increase and a sort of metamagnetic transition that appears to be responsible for a complete suppression of the exchange bias effect in CaMn0.9Nb0.1O3 at high magnetic field. © 2015 Elsevier B.V. All rights reserved.

Published
2015
Full Text
View/download PDF

3. Unconventional exchange bias effect driven by phase separation in basically antiferromagnetic Sm0.1Ca0.6Sr0.3MnO3

Author

Roman Puzniak, G. Jung, G. Gorodetsky, A. Wisniewski, I. M. Fita, P. Iwanowski, C. Martin, V. Markovich, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Ben-Gurion University of the Negev (BGU), Institute of Physics, Polish Academy of Sciences, Polska Akademia Nauk = Polish Academy of Sciences (PAN), National Academy of Sciences of Ukraine (NASU), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Magnetism, Phase separation, 02 engineering and technology, 01 natural sciences, Magnetization, chemistry.chemical_compound, 0103 physical sciences, Materials Chemistry, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, 010306 general physics, Condensed matter physics, Magnetic moment, Chemistry, Mechanical Engineering, Metals and Alloys, Hysteresis loop, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Magnetic hysteresis, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Exchange bias, Mechanics of Materials, Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology, Spontaneous magnetization, Néel temperature, AFm phase
Abstract

International audience; Magnetic investigations, focused on the uncommon behavior of the exchange bias (EB) effect, have been performed for basically antiferromagnetic (AFM) electron doped manganite Sm0.1Ca0.6Sr0.3MnO3. The studied system in the ground state exhibits a heterogeneous spin configuration consisting of the C-type antiferromagnetic phase with the Néel temperature TN-C ≈ 150 K, the G-type AFM phase with the Néel temperature TN-G ≈ 70 K, and a FM-like phase with very weak spontaneous magnetic moment. The phase separation, into two different AFM phases and a FM-like phase at the temperatures below TN-G, leads to unusual magnetic properties, such as narrowing of magnetic hysteresis loops in field cooling process, unconventional EB effect associated with spontaneous magnetization at temperatures below TN-C, strong magnetic field dependence of the negative exchange bias at fields below 100 Oe turning into practically field independent one for fields above 0.5 kOe, significant shift of EB with temperature with a change of the sign from negative at 10 K to positive above 40 K. The atypical magnetic properties are discussed and related to two different interfaces appearing between coexisting magnetic phases. © 2014 Elsevier B.V. All rights reserved.

Published
2015
Full Text
View/download PDF

4. Volume expansion contribution to the magnetism of atomically disordered intermetallic alloys

Author

M. Amboage, Estibaliz Apiñaniz, J.S. Muñoz, François Baudelet, Roman Puzniak, Santiago Suriñach, Josep Nogués, Jordi Sort, I. M. Fita, Olivier Mathon, Fernando Plazaola, J. S. Garitaonandia, Matteo d'Astuto, Maria Dolors Baró, Institució Catalana de Recerca i Estudis Avançats (ICREA), Fisika Aplikatua I Saila, Ingenieritza Goi Eskola Teknikoa, Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), European Synchrotron Radiation Facility (ESRF), Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics, Polska Akademia Nauk = Polish Academy of Sciences (PAN), Donetsk Institute for Physics and Engineering named after A.A. Galkin, National Academy of Sciences of Ukraine (NASU), Fisika Aplikatua II Saila, Zientzia eta Teknologia Fakultatea, Departament de Física, Universitat Autònoma de Barcelona (UAB), Elektrika eta Elektronika Saila, Zientzia eta Teknologia Fakultatea, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institute of Physics, Polish Academy of Sciences, Departament de Fisica, Universitat Autonoma de Barcelona, Elektrika eta Elektronika Saila, Fisika Aplikatua II Sail Atala [Euskal Herriko Unibertsitatea], Zientzia eta Teknologia Fakultatea [Euskal Herriko Unibertsitatea], Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU)-Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Diffraction, Materials science, Magnetism, Intermetallic, 02 engineering and technology, 01 natural sciences, Condensed Matter::Disordered Systems and Neural Networks, PACS numbers : 75.50.Bb, 61.50.Ks, 64.60.Cn, 71.20.Lp, Condensed Matter::Materials Science, Condensed Matter::Superconductivity, 0103 physical sciences, phase transformations, Physics::Atomic Physics, 010306 general physics, Electronic band structure, 75.50.Bb, 61.50.Ks, 64.60.Cn, 71.20.Lp, Condensed matter physics, Magnetic moment, pressure effects, FEAL, Dichroism, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Fe alloys, statistical mechanics of model systems, Magnetic shape-memory alloy, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], Intermetallic compounds, Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology
Abstract

The origin of magnetism in atomically disordered transition-metal–nonmagnetic i.e., FeAl alloys has been investigated by dichroism and diffraction measurements at high pressure and by band structure calculations. The results show that, in contrast to earlier studies, besides the effects of the local environment of the magnetic ions, disorder-induced lattice changes play a key role in the magnetic properties of these systems. We demonstrate experimentally and theoretically that about 35–45% of the magnetic moment of Fe60Al40 alloys arises from lattice expansion effects induced during the disordering process. Such large effects in Fe60Al40 could actually be related to the moment-volume instability observed in these alloys.

Published
2004
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results