Magnetism of Co-doped titania thin films prepared by spray pyrolysis

Manivannan, A.; Seehra, M. S.; Majumder, S. B.; Katiyar, R. S.
July 2003
Applied Physics Letters;7/7/2003, Vol. 83 Issue 1, p111
Academic Journal
Co-doped TiO[SUB2] (anatase) films prepared by spray pyrolysis at 500°C are investigated for the possible existence of room temperature ferromagnetism (RTF). These films were characterized by x-ray diffraction, Raman spectroscopy, and x-ray photoelectron spectroscopy at room temperature, followed by studies of the temperature and magnetic field dependence of the magnetization by squid magnetometry. For Co doping of upto 10 at. %, no phase other than anatase could be detected, and there is no RTF in these films. Instead, the magnetic susceptibility χ fits the modified Curie-Weiss law χ=χ[SUB0]+C/(T+θ), with θ≃5 K and magnitude of C consistent with Co[SUP2+] paramagnetism in Ti[SUB1-x]Co[SUBx]O[SUB2-x]. Only for T≤5 K, a hysteresis loop with coercivity H[SUBc]=200 Oe is observed. These observations suggest Co[SUP2+] paramagnetism, with exchange interaction becoming important for T ≤5 K in the case of 10% Co/TiO[SUB2] films.


Related Articles

  • Unusual magnetic behavior of SiCN/multiwalled carbon nanotubes nanocomposites. Francis, A.; Riedel, R. // Journal of Applied Physics;Apr2009, Vol. 105 Issue 7, p07A318 

    Multiwalled carbon nanotubes (MWCNTs) have been dispersed homogeneously throughout a preceramic polysilazane matrix. The homogenized mixture was then warm pressed and subsequently pyrolyzed in Ar atmosphere at 1100 °C, yielding an amorphous silicon carbonitride (SiCN)/MWCNT nanocomposite. The...

  • Dispersion of the pinning field direction of a ferromagnet/antiferromagnet coupled system. Hou, Chunhong; Chen, Jian; Kief, Mark T.; Gao, Zheng; Mao, Sining; Pokhil, Taras // Applied Physics Letters;1/8/2001, Vol. 78 Issue 2, p237 

    The exchange bias field of a ferromagnet/antiferromagnet bilayer is usually measured by the unidirectional shift of the hysteresis loop of the ferromagnetic layer. The exchange bias field results from interfacial exchange coupling between the spins in the ferromagnetic and antiferromagnetic...

  • Model of ferromagnetic resonance in granular magnetic solids. Verdes, C. G.; Ruiz-Diaz, B.; Thompson, S. M.; Chantrell, R. W.; Stancu, Al. // Journal of Applied Physics;6/1/2001, Vol. 89 Issue 11, p7475 

    Micromagnetic simulations of ferromagnetic fine particle systems have been used to study the effect of various parameters on the hysteresis loops and on the ferromagnetic resonance (FMR) curves. Systematic calculations show that the effect of the dipolar interactions on such systems...

  • A high-performance hysteresis loop tracer. Kulik, Tadeusz; Savage, Howard T.; Hernando, Antonio // Journal of Applied Physics;5/15/1993, Vol. 73 Issue 10, p6855 

    Presents information on a study which developed a hysteresis loop tracer to measure quasistatic hysteresis loops of soft ferromagnetic materials. Schematic diagram of the hysteresis loop measuring system; Description of the software; Examples of hysteresis loops.

  • Improvement of (004) texturing by slow growth of Nd doped TiO2 films. Ali, A.; Yassitepe, E.; Ruzybayev, I.; Ismat Shah, S.; Bhatti, A. S. // Journal of Applied Physics;Dec2012, Vol. 112 Issue 11, p113505 

    In this work, we present preferred (004) texturing of sputter deposited titanium dioxide (TiO2) films on glass substrates as a consequence of Nd doping at very slow growth rate. Nd concentration was varied from 0.0 to 2.0 atomic percent (at. %) in TiO2 thin films deposited under identical growth...

  • Ferromagnetic/antiferromagnetic exchange coupling in SrFe[sub 12]O[sub 19]/CoO composites. Liu, X.S.; Gu, B.X.; Zhong, W.; Jiang, H.Y.; Du, Y.W. // Applied Physics A: Materials Science & Processing;2003, Vol. 77 Issue 5, p673 

    The surface of SrFe[SUB12]O[SUB19] coated with a CoO layer reveals a strong exchange bias characterized by magnetic hysteresis loops. The low-temperature coercivity, H[SUBC], and the squareness, M[SUBR]/M[SUBS], of a permanent magnet of SrFe[SUB12]O[SUB19]/CoO powder prepared by the sol-gel...

  • Tuning exchange bias. Miltenyi, P.; Gierlings, M. // Applied Physics Letters;10/11/1999, Vol. 75 Issue 15, p2304 

    Studies the control of the exchange bias shift of the hysteresis loop in antiferromagnetic/ferromagnetic layer systems by cooling in zero field from different magnetization states. Determination of moderate cooling fields; Selection of the desired value of the exchange bias via a postgrowth...

  • Magnetization processes in ferromagnetic cubes. Schabes, Manfred E.; Bertram, H. Neal // Journal of Applied Physics;8/1/1988, Vol. 64 Issue 3, p1347 

    Presents a study which numerically investigated the magnetization process in ferromagnetic cubes. Cubic discretization procedure of the micromagnetic energy functional; Mathematical framework for describing the ferromagnetic particle; Computation of the complete hysteresis loops for a wide...

  • Hysteresis modeling of anisotropic and isotropic nanocrystalline hard magnetic films. Cornejo, D. R.; Azevedo, A.; Rezende, S. M. // Journal of Applied Physics;5/15/2003, Vol. 93 Issue 10, p6623 

    In the Hauser model, the magnetic state of a system is obtained by minimizing the so-called total energy function for a statistical set of magnetic domains. In this article, this energetic model of ferromagnetic materials is used in order to calculate hysteresis loops of isotropic and...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics