Study of the structural and magnetic properties of rutile ($\mathrm{TiO}_2$) heavily implanted with iron ions

I. R. Vakhitov^a, V. I. Nujdin^b, Y. N. Osin^b, R. I. Khaibullin<sup>ba

a</sup> Kazan State University
^b Zavoisky Physical Technical Institute, Kazan Scientific Center of the Russian Academy of Sciences

Abstract: Single-crystalline (100)- and (001)-films of titanium dioxide ($\mathrm{TiO}_2$) were implanted by Fe ions with an energy of 40 keV with a high dose of irradiation of $1.5\cdot10^{17}$ ion/cm$^2$. Structural and magnetic properties of the surface layer of the irradiated samples were studied using scanning electron microscopy and inductive magnetometry. As a result of high-dose implantation the originally transparent $\mathrm{TiO}_2$ films became grey with strong metallic luster due to the formation of metal iron nanoparticles in the irradiated surface layer of rutile. Magnetic measurements showed that the iron-implanted samples are ferromagnetic at room temperature. The ferromagnetism shows easy-plane anisotropy, which is typical for thin ferromagnetic films. In addition, 2- and 4-fold magnetic anisotropy in the surface plane was revealed for the (100)- and (001)-samples, respectively. The latter observation indicates that the iron nanoparticles synthesized by ion implantation are coherently embedded in the tetragonal crystal structure of rutile.

Keywords: ion implantation, ferromagnetism, magnetic anisotropy.

UDC: 535.39

Received: 30.06.2010