Revival of ferromagnetic behavior in charge-ordered Pr0.75Na0.25MnO3 manganite by ruthenium doping at Mn site and its MR effect

• Main Authors: Chen, SK (Author), Elyana, E (Author), Kamil, SA (Author), Mohamed, Z (Author), Supardan, SN (Author), Yahya, AK (Author)
• Format: Article
• Language: English
• Published: 2018
• Subjects: Charge ordering; COLOSSAL MAGNETORESISTANCE; Double-exchange mechanism; GRIFFITHS PHASE; Jahn-Teller effect; LOCAL-STRUCTURE; MAGNETIC-PROPERTIES; MAGNETOCALORIC PROPERTIES; Perovskite manganite; RU; Ru doping; SEPARATION; SUBSTITUTION; TEMPERATURE; TRANSPORT-PROPERTIES
• Online Access: View Fulltext in Publisher

 Ru doping in charge-ordered Pr(0.75)Na(0.25)Mn(1-x)RuxO(3) (x = 00.1) manganites was studied to investigate its effect on structure, electrical transport, magnetic properties, and magnetotransport properties. DC electrical resistivity (rho), magnetic susceptibility, and chi' measurements showed that sample x = 0 exhibits insulating behavior within the entire temperature range and antiferromagnetic (AFM) behavior below the charge-ordering (CO) transition temperature T-CO of 221 K. Ru4+ substitution (x>0.01) suppressed the CO state, which resulted in the revival of paramagnetic to ferromagnetic (FM) transition at the Curie temperature T-c, increasing from 120 K (x = 0.01) to 193 K (x = 0.1). Deviation from the Curie-Weiss law above T-c in the 1/chi' versus T plot for x = 0.01 doped samples indicated the existence of Griffiths phase with Griffith temperature at 169 K. Electrical resistivity measurements showed that Ru4+ substitution increased the metallic-to-insulating transition temperature T-MI from 144 K (x = 0.01) to 192 K (x = 0.05) due to enhanced double-exchange mechanism, but T-MI decreased to 176 K (x = 0.1) probably due to the existence of AFM clusters within the FM domain. The present work also discussed the possible theoretical models at the resistivity curve of Pr0.75Na0.25Mn1-xRuxO3 (x = 0-0.1) for the entire temperature range.