Development of Ferromagnetic Superspins in Bare Cu Nanoparticles by Electronic Charge Redistribution

International Journal of Molecular Sciences

Erdembayalag Batsaikhan²  Yen-Cheng Chen²  Chi-Hung Lee²  Hsiao-Chi Li²  Wen-Hsien Li¹ 

[1] Department of Physics, National Central University, Jhongli 32001, Taiwan;

关键词: Cu nanoparticle;    ferromagnetic superspin;    electronic charge density;   

DOI  :  10.3390/ijms161023165

来源: mdpi

【 摘 要 】

We report on the results of investigating the ferromagnetic properties of bare Cu nanoparticles. Three sets of bare Cu nanoparticle assemblies with mean particle diameters of 6.6, 8.1, and 11.1 nm were fabricated, employing the gas condensation method. Curie-Weiss paramagnetic responses to a weak driving magnetic field were detected, showing the appearance of particle superspins that overcomes the diamagnetic responses from the inner core. The isothermal magnetization displays a Langevin field profile together with magnetic hysteresis appearing even at 300 K, demonstrating the existence of ferromagnetic superspins in the Cu nanoparticles. Shifting of a noticeable amount of electronic charge from being distributed near the lattice sites in bulk form toward their neighboring ions in nanoparticles was found. The extended 3d and 4s band mixture are the main sources for the development of localized 3d holes for the development of ferromagnetic particle superspins in Cu nanoparticles.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.