Large tunability of Néel temperature by growth-rate-induced cation inversion in Mn-ferrite nanoparticles.

Autor: Aria Yang, Chinnasamy, C. N., Greneche, J. M., Yajie Chen, Yoon, Soack D., Kailin Hsu, Vittoria, C., Harris, V. G.
Předmět:
Zdroj: Applied Physics Letters; 3/16/2009, Vol. 94 Issue 11, p113109, 3p, 1 Chart, 3 Graphs
Abstrakt: The tuning of Néel temperature by greater than 100 K in nanoparticle Mn-ferrite was demonstrated by a growth-rate-induced cation inversion. Mn-ferrite nanoparticles, having diameters from 4 to 50 nm, were synthesized via coprecipitation synthesis. The Néel temperature (TN) increased inversely to the cation inversion parameter, δ (i.e., defined as (Mn1-δFeδ)tet[MnδFe2-δ]octO4). Concomitantly, TN increased with increased particle growth rate and particle size. These results unambiguously establish cation inversion as the dominant mechanism in modifying the superexchange leading to enhanced TN. The ability to tailor TN enables greater flexibility in applying nanoparticle ferrites in emerging technologies. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index