55Mn NMR in Ferromagnetic Double Perovskites La1-xBixmn0.5Ni0.5O3

• Published in: Journal of the Physical Society of Japan Vol. 78; no. 11
• Main Authors: ASAI, Kichizo, KAWAKAMI, Takafumi, ENOSHITA, Shumpei, SHIOZAWA, Masanori, KOBAYASHI, Yoshihiko
• Format: Journal Article
• Language: English
• Published: Tokyo Physical Society of Japan 01-11-2009; The Physical Society of Japan
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Nuclear magnetic resonance and relaxation; Physics; Mn; Hyperfine magnetic field; multiferroic; Curie point; supertransferred hyperfine interaction; Bi; Ferromagnetic materials; Oxides; Perovskites; Covalent bonds; O; Ferroic material; double perovskite; La; Mn NMR; Ferromagnetism; Hyperfine interactions; Nuclear magnetic resonance; Ni
• ISSN: 0031-9015; 1347-4073

The hyperfine magnetic field HHF at 55Mn in ferromagnetically ordered double perovskites La1-xBixMn0.5Ni0.5O3 with 0≤x≤0.9 were investigated by NMR at 1.8 K. HHF decreases with increasing Bi content x from -258 kOe at x=0 to approximately -280 kOe at x=0.9, which is attributed to a reduction in the positive supertransferred hyperfine magnetic field, HSTHF, from neighboring Ni2+ ions. The reduction in HSTHF caused by the Bi substitution suggests that the covalent character of Ni2+-O2--Mn4+ bonds decreases in competition with that of Bi3+-O2- bonds. The decrease in the ferromagnetic Curie temperature of the present system with increasing x is quantitatively interpreted with the decreasing covalent character of Ni2+-O2--Mn4+ bonds.