2017/09/06 by Ravi Prakash, Rishabh Shukla, Prakash, Ravi +6
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic Properties of Alloys #Magnetic and transport properties of perovskites and related materials #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Rare-earth and actinide compounds
paper · pdf · doi:10.48550/arxiv.1709.01745
openalex publication_date 2017/09/06 · openalex created_date 2017/09/15 · openalex updated_date 2026/07/28
We use the x-ray diffraction, magnetic susceptibility, isothermal magnetization, and photoelectron spectroscopy to study the structural, magnetic and electronic properties of La(1-x)AxCoO3 (A= Sr, Ca; x= 0 -- 0.2) nanoparticles. The Rietveld refinements of room temperature powder x-ray diffraction data confirm the single phase and the rhombohedral crystal structure with R3C space group. We find drastic changes in the magnetic properties and spin-states with Sr/Ca substitution (hole doping). For x= 0 sample, the magnetic measurements show a ferromagnetic transition at T\rm C≈85 K, which shifted significantly to higher temperatures with hole doping; simultaneously a significant increase in the spontaneous magnetic moment has been observed. Whereas, the coercive field H\rm C values are 7, 4.4 and 13.2~kOe for x= 0, 0.2 (Sr), and 0.2(Ca) samples. Furthermore, the FC magnetization shows a ferromagnetic Brillouin function like behavior at low temperatures for Ca samples. We demonstrate that the Sr/Ca substitution increases the population of IS (Co3+) and LS (Co4+) states and tune the ferromagnetism in nanoparticles via double-exchange interactions between Co3+-- Co4+. Our results suggest an important role of hole carriers and nano-size effect in controlling the spin-state and magnetism in La(1-x)AxCoO3 nanoparticles.