Colossal magnetoresistance in epitaxial La(1−x−y)NayMnO3 thin film

Abstract

We have synthesized La0.83Na0.11MnO2.93 by heating La2O3 and MnCO3 in NaCl melt at 900 °C. The exact composition was arrived by analyzing each ion by an independent chemical method. The compound crystallized in a rhombohedral structure and showed an insulator-to-metal transition at 290 K. Epitaxial thin films were fabricated on LaAlO3 (100) using a pulsed laser deposition technique. The film also showed an insulator-to-metal transition at 290 K. Magnetoresistance [ΔR/R0=(RH−R0)/R0] was −71% near the insulator-to-metal transition temperature of 290 K at 6 T magnetic field.

Mechanochemical effects on microstructure and transport properties of nanocrystalline La0.8Na0.2MnO3 ceramics

“…Moreover, as the milling time increases, the T IM is decreased and the resistivity is continuously increased, which can be attributed to the decrease of the crystalline size [11,12,20,21]. From Table 1, it can be observed that the T IM of the sample MA0 is about 270 K, which is lower than that of the previously reports and it may be related to the smaller crystalline size in our experiment [23][24][25][26][27]. As for the origin of the decrease of the T IM and the increase of the resistivity, the reason is discussed as follows.…”

“…Unlike divalent element-doped manganites, the monovalent elementdoped manganites have some interesting features. One of the most important features is that it is possible to achieve an equal amount of holes with a lower cation substitution for La sites, which will result in lower cation disorder [23,24]. In the monovalent element-doped manganites, the La 1−x Na x MnO 3 is a typical system and it has relatively large MR values near room temperature [23][24][25][26][27].…”

Synthesis, Structure, and Properties of Sodium or Potassium-Doped Lanthanum Orthomanganites from NaCl or KCl Flux

“…Since Na or K can substitute for La (13), we obtained ferromagnetic Na or K doped lanthanum manganites. Among the large number of Na or K doped lanthanum manganites synthesized by this method, epitaxial thin film of La Na MnO was made by pulsed laser deposition, and the thin film showed over 70% CMR at 290 K in 6T magnetic field (14). Composition of these phases has been derived by chemical analysis of La, Na/K, Mn, and oxygen independently.…”

Low Frequency Internal Friction Study of Phase Transition in La0.95K0.05MnO3 Bulk Materials

“…Due to the difference in valence states, the divalent and the monovalent ion doping in LaMnO 3 can result in different consequences. In both the monovalent and the divalent ion doping manganites similar electrical and magnetic properties are obtained [6][7][8][9][10][11], but usually the monovalent ion doped mangnites have a higher T C [8], which is important when considering the practical application of these kinds of materials. In the magnetoresistance materials, the CMR is generally associated with a phase transition (I-M, PM-FM).…”