Jumaeda Jatmika, Suci Winarsih, Agung Imaduddin, Risdiana
{"title":"Enhancing low field magnetoresistance in La0.7Ca0.25Sr0.05MnO3/Mn3O4 composite nanoparticles: unveiling its transport mechanism","authors":"Jumaeda Jatmika, Suci Winarsih, Agung Imaduddin, Risdiana","doi":"10.1007/s10971-024-06627-y","DOIUrl":null,"url":null,"abstract":"<div><p>This work explores the low-field magnetoresistance (LFMR) and transport properties of La<sub>0.7</sub>Ca<sub>0.25</sub>Sr<sub>0.05</sub>MnO<sub>3</sub>/Mn<sub>3</sub>O<sub>4</sub> composite nanoparticles synthesized via the sol-gel method and sintered at temperatures from 700 °C to 900 °C. We investigate particle size (28–32 nm), Mn<sub>3</sub>O<sub>4</sub> fraction, structural phases, and their effects on resistivity and LFMR. Rietveld refinement confirms the coexistence of distorted monoclinic and spinel structures, with an increasing Mn<sub>3</sub>O<sub>4</sub> fraction correlating to notable shifts in resistivity and LFMR. Temperature-dependent resistivity measurements reveal a transition from metallic to insulator state, with the 30 nm particle and 19% Mn<sub>3</sub>O<sub>4</sub> exhibiting lowest resistivity due to reduce in grain boundary effects and the highest conduction bandwidth. A non-monotonous dependence of resistivity at different particle size and Mn<sub>3</sub>O<sub>4</sub> fraction has been observed. It is suggested that resistivity in our composite system is influenced by the interplay of grain boundary contributions, Mn<sub>3</sub>O<sub>4</sub> phase distribution, and conduction bandwidth. LFMR reaches up to 30% at 5 K and 5 kOe, exceeding values in similar composite systems. These results emphasize the role of Mn<sub>3</sub>O<sub>4</sub> as an insulating phase and highlight the impact of nanoparticle size on the enhancement of LFMR, offering insights into optimizing LFMR in such composites.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":"113 2","pages":"399 - 412"},"PeriodicalIF":2.3000,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Sol-Gel Science and Technology","FirstCategoryId":"88","ListUrlMain":"https://link.springer.com/article/10.1007/s10971-024-06627-y","RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}
引用次数: 0
Abstract
This work explores the low-field magnetoresistance (LFMR) and transport properties of La0.7Ca0.25Sr0.05MnO3/Mn3O4 composite nanoparticles synthesized via the sol-gel method and sintered at temperatures from 700 °C to 900 °C. We investigate particle size (28–32 nm), Mn3O4 fraction, structural phases, and their effects on resistivity and LFMR. Rietveld refinement confirms the coexistence of distorted monoclinic and spinel structures, with an increasing Mn3O4 fraction correlating to notable shifts in resistivity and LFMR. Temperature-dependent resistivity measurements reveal a transition from metallic to insulator state, with the 30 nm particle and 19% Mn3O4 exhibiting lowest resistivity due to reduce in grain boundary effects and the highest conduction bandwidth. A non-monotonous dependence of resistivity at different particle size and Mn3O4 fraction has been observed. It is suggested that resistivity in our composite system is influenced by the interplay of grain boundary contributions, Mn3O4 phase distribution, and conduction bandwidth. LFMR reaches up to 30% at 5 K and 5 kOe, exceeding values in similar composite systems. These results emphasize the role of Mn3O4 as an insulating phase and highlight the impact of nanoparticle size on the enhancement of LFMR, offering insights into optimizing LFMR in such composites.
期刊介绍:
The primary objective of the Journal of Sol-Gel Science and Technology (JSST), the official journal of the International Sol-Gel Society, is to provide an international forum for the dissemination of scientific, technological, and general knowledge about materials processed by chemical nanotechnologies known as the "sol-gel" process. The materials of interest include gels, gel-derived glasses, ceramics in form of nano- and micro-powders, bulk, fibres, thin films and coatings as well as more recent materials such as hybrid organic-inorganic materials and composites. Such materials exhibit a wide range of optical, electronic, magnetic, chemical, environmental, and biomedical properties and functionalities. Methods for producing sol-gel-derived materials and the industrial uses of these materials are also of great interest.