Cerámicas magnetorresistivas. Progresos recientes: desde el entendimiento básico a las aplicaciones

Abstract

Magnetoresistive ceramics, based on half-metallic ferromagnetic oxides have received renewed attention in the last few years because of their possible applications. Here, we review some recent progress on the development of magnetoresistive ceramic materials such as La 2/3 Sr 1/ 3 MnO 3 and Sr 2 FeMoO 6 ceramic materials. We shall revisit their basic properties, the strategies that have been employed to understand and to improve their intrinsic properties, pushing the limits of their operation at temperatures well above room-temperature, and the development of some applications. This effort has required the contribution of a number of actors. Starting from research laboratories, it has progressively involved industries that nowadays are able to supply high quality raw-materials or to manufacture magnetoresistive components at large scale. Keywords: magnetoresistive ceramics, manganese oxides, magnetic sensorsCerámicas magnetorresistivas. Progresos recientes: desde el entendimiento básico a las aplicaciones.Las cerámicas magnetorresistivas, basadas en óxidos semi-metálicos ferromagnéticos han recibido una renovada atención en los últimos años debido a sus posibles aplicaciones. Se revisan aquí algunos de los recientes progresos en el desarrollo de materiales cerámicos magnetorresistivos como La 2/3 Sr 1/3 MnO 3 y Sr 2 FeMoO 6 . Se revisitan sus propiedades básicas, las estrategias empleadas para entender y mejorar sus propiedades intrínsecas, llevando sus límites de operación a temperaturas muy por encima de temperatura ambiente, y el desarrollo de algunas aplicaciones. Este esfuerzo ha requerido al contribución de un gran número de actores. Comenzando por laboratorios de investigación, se ha implicado progresivamente a industrias que hoy en día están capacitadas para suministrar materias primas de alta calidad o para fabricar componentes magnetorresistivos a gran escala. Palabras clave: cerámicas magneto-resistivas, óxidos de manganeso, sensores magnéticos

Half-metallic double perovskite oxides: recent developments and future perspectives

“…In 1983 Rob de Groot et al first proposed the concept of half-metallicity; 6 since then, numerous HM materials have been discovered. 7–10 Normally they are categorized into half- and full-Heusler alloys, 7 zinc blende structured materials (such as MnBi, CrSb), transition-metal magnetic oxides such as Fe 3 O 4 and CrO 2 , perovskite manganite oxides ( e.g. , La 2/3 Ba 1/3 MnO 3 , La 2/3 Sr 1/3 MnO 3 ), DP oxides such as A 2 FeMoO 6 (where A = Ca, Sr, Ba), Sr 2 FeMoO 6 (SFMO), and Sr 2 FeReO 6 (SFRO).…”

“…In 1983 Rob de Groot et al first proposed the concept of half-metallicity; 6 since then, numerous HM materials have been discovered. [7][8][9][10] Normally they are categorized into halfand full-Heusler alloys, 7 zinc blende structured materials (such as MnBi, CrSb), transition-metal magnetic oxides such as Fe 3 O 4 and CrO 2 , perovskite manganite oxides (e.g., La 2/3 Ba 1/3 MnO 3 , La 2/3 Sr 1/3 MnO 3 ), DP oxides such as A 2 FeMoO 6 (where A = Ca, Sr, Ba), Sr 2 FeMoO 6 (SFMO), and Sr 2 FeReO 6 (SFRO). 4,[7][8][9] In order to develop high-performance spintronic devices that can be operated at room temperature (RT), HM materials should meet the following requirements: they should have (i) high Curie temperature (T c , much over RT), (ii) a wide half-metallic gap (D HM ) to block the spin-flip transition of carriers caused by thermal excitation, and (iii) a large bulk magnetocrystalline anisotropy energy to prevent the random and uncontrollable spin switching induced by thermal fluctuation.…”

“…[7][8][9][10] Normally they are categorized into halfand full-Heusler alloys, 7 zinc blende structured materials (such as MnBi, CrSb), transition-metal magnetic oxides such as Fe 3 O 4 and CrO 2 , perovskite manganite oxides (e.g., La 2/3 Ba 1/3 MnO 3 , La 2/3 Sr 1/3 MnO 3 ), DP oxides such as A 2 FeMoO 6 (where A = Ca, Sr, Ba), Sr 2 FeMoO 6 (SFMO), and Sr 2 FeReO 6 (SFRO). 4,[7][8][9] In order to develop high-performance spintronic devices that can be operated at room temperature (RT), HM materials should meet the following requirements: they should have (i) high Curie temperature (T c , much over RT), (ii) a wide half-metallic gap (D HM ) to block the spin-flip transition of carriers caused by thermal excitation, and (iii) a large bulk magnetocrystalline anisotropy energy to prevent the random and uncontrollable spin switching induced by thermal fluctuation. 11 Although diverse HM materials have been theoretically predicted, most of them are not capable of fulfilling the above criteria simultaneously.…”

Synthesis and Characterization of Nickel Ferrite-Barium Titanate Ceramic Composites

“…This effect takes place in mixed or compound materials that have ferro-piezoelectric and magnetoestrictive phases and results from the linking of both phases. The magnetoelectric effect in compound materials is analysed from the Van Suchetelene approach, as a result of the properties of each phase [15,16]. A suitable combination of the two phases must lead jointly to the coexistence of piezoelectric and piezomagnetic/ magnetostrictive phases.…”

Synthesis and characterization of electroceramics with magnetoelectric properties

“…The magnetoelectric effect in compound materials is analysed from the Van Suchetelene approach, as a result of the properties of each phase. 15 A suitable combination of the two phases must lead jointly to the coexistence of piezoelectric and piezomagnetic phases or a combination of magnetostrictive and piezoelectric phases 16 . In this work, we try to verify the coexistence of phases in ferroelectric-ferromagnetic (ferric) compounds in which the existence of magnetoestrictive effects are clear.…”