J. H. Yin

Room-temperature ferromagnetism in carbon-doped ZnO

We report magnetism in carbon doped ZnO. Our first-principles calculations based on density functional theory predicted that carbon substitution for oxygen in ZnO results in a magnetic moment of 1.78

Nanocrystalline Co-ferrite films with high perpendicular coercivity

\mu_B

Magnetic anisotropy and high coercivity of epitaxial Co-ferrite films prepared by pulsed laser deposition

per carbon. The theoretical prediction was confirmed experimentally. C-doped ZnO films deposited by pulsed laser deposition with various carbon concentrations showed ferromagnetism with Curie temperatures higher than 400 K, and the measured magnetic moment based on the content of carbide in the films (

FePt films fabricated by electrodeposition

1.5 - 3.0 \mu_B

Effects of heat treatment and magnetoannealing on nanocrystalline Co-ferrite powders

per carbon) is in agreement with the theoretical prediction. The magnetism is due to bonding coupling between Zn ions and doped C atoms. Results of magneto-resistance and abnormal Hall effect show that the doped films are

High-coercivity Co-ferrite thin films on SiO/sub 2/(100) substrate prepared by sputtering and PLD

n

Effect of Sputtered Seed Layer on Electrodeposited NiFe/Cu Composite Wires

-type semiconductors with intrinsic ferromagnetism. The carbon doped ZnO could be a promising room temperature dilute magnetic semiconductor (DMS) and our work demonstrates possiblity of produing DMS with non-metal doping.

MAGNETIC PROPERTIES OF NANOCRYSTALLINE CO-FERRITE FILMS DEPOSITED ON SINGLE-CRYSTAL SiO2 SUBSTRATES USING PULSED LASER DEPOSITION

Co-ferrite films were prepared using pulsed laser deposition at low substrate temperatures in this work. Magnetic properties of these films have been investigated in the function of substrate temperature and film thickness. A perpendicular coercivity as high as 12.5kOe has been achieved in the Co-ferrite film with a thickness of 33nm deposited at 550°C. The high coercivity mechanism is possibly associated with nanocrystalline structure, textured structure, and presence of relatively large residual strain.

Microstructure Evolution of Ni

CoFe2O4 films with different thicknesses (40–200nm) were prepared on sapphire using pulsed laser deposition at different substrate temperatures. The films on (0001) sapphire showed a (111) epitaxial structure even at a low deposition temperature of 150°C. The coercivity up to 8.8kOe could be achieved in the 40nm film on sapphire deposited at 550°C. By comparison, the 33nm film on quartz possesses a nanocrystalline structure with the grain size below 20nm as well as a strong (111) preferential texture. The highest coercivity (12.5kOe) up to now was obtained in the 33nm Co-ferrite films. The study also revealed that high coercivity and large perpendicular anisotropy of these Co-ferrite thin films may be related to the textured structure and large residual strain.

_{80}

In this work, we have fabricated FePt films with a thickness in the range of 0.1–1μm using the combination of electrodeposition and postannealing. FePt films with a composition around Fe50Pt50 were formed by electrodeposition onto the Si (100) substrates with an underlayer of Au, Ag, or Cu, and subsequently annealed at a temperature in the range of 200–900°C for 20min. From our x-ray diffraction analysis, the L10 FePt phase started to form after annealing at 400°C for the film deposited on the Au underlayer. The highest coercivity (10kOe) was found after annealing at 600°C. When the FePt was deposited on the Ag underlayer, a high coercivity over 15kOe with an out-of-plane anisotropy has been achieved after annealing at 700–800°C. The magnetic anisotropy was associated with the crystallographic texture. The magnetic properties of FePt films deposited on the Cu underlayer were relatively poor with lower values of coercivity (4–5kOe as the maximum coercivity), probably due to the large grain size.