Abstract

This research study was aimed at determining the temperature dependence of Ferromagnetic Resonance (FMR), the recorded signal versus angle and the magnetic property of the 15 uc thick La_0.7Sr_0.3MnO₃ (LSMO) thin film sample on a single crystalline SrTiO₃ (STO) substrate at 150 K and 9.75 GHz using ferromagnetic resonance technique. We observed from the Ferromagnetic Resonance (FMR) spectra at various temperatures (150, 200 and 250 K, respectively) that as the temperature increases, the FMR spectra shifts to higher fields and this might be as a result of transition into the ferromagnetic state. The recorded signal versus the angle showed an unusual phenomenon at all temperatures (150, 200 and 250 K, respectively) and this might be due to shape effects and other contributing factors such as misfit strain and crystal misfit in the LSMO thin film. The plot of resonance field versus the in-plane angle showed a spectrum which was sinusoidal-like in nature with maximum and minimum curvatures. The resonance position and the Full Width Half Maximum (FWHM) of the 15 uc thick LSMO thin film were 718.15 and 561.45 Oe, respectively. The 15 uc thick LSMO thin film displayed ferromagnetic resonance at 150, 200 and 250 K, respectively and this has been confirmed using the surface plot.

Keywords:

Crystal misfit, full width half maximum, magnetic anisotropy, magnetization, resonance position, unit cell,

References

1. Alejandro, G., L.B. Steren, H. Pastoriza, D. Vega, M. Granada, J.C. Sanchez Rojas, M. Sirena and B. Alascio, 2010. Magnetoresistance effect in (La, Sr) MnO3 bicrystalline films. J. Phys-Condens. Mat., 22: 1-11.
   
2. Bah, R., D. Bitok, R.R. Rakhimov and M.M. Noginova, 2006. Ferromagnetic resonance studies on colossal magnetoresistance film: Effects of homogeneity and light illumination. J. Appl. Phys., 99(8): 08Q312-08Q312-3.
   CrossRef    
3. Beaujour, J.M., D. Ravelosona, I. Tudosa, E. Fullerton and A.D. Kent, 2009. Ferromagnetic resonance linewidth in ultrathin films with perpendicular magnetic anisotropy. Phys. Rev. B, 80: 180415.
   CrossRef    
4. Coey, J.M.D, M. Viret and S. Von Molnar, 1999. Mixed-valence manganites. Adv. Phys., 48(2): 167-293.
   CrossRef    
5. Fang, W. and C.Y. Lo, 2000. On the thermal expansion coefficient of thin films. Sensors Actuator., 82: 310-314.
   CrossRef    
6. Farle, M., 1998. Ferromagnetic resonance of ultrathin metallic layers. Rep. Prog. Phys., 61: 755-826.
   CrossRef    
7. Farle, M., J. Lindner and K. Baberschke, 2000. Ferromagnetic resonance of Ni (111) and Re (0001). J. Magn. Magn. Mater., 212: 301-306.
   CrossRef    
8. Gosnet, A.M.H. and J.P. Renard, 2003. CMR manganites: Physics, thin films and devices. J. Phys. Appl. Phys., 36: R127-R150.
   CrossRef    
9. Griffiths, J.H.E., 1946. Nature, 158: 670.
   CrossRef    
10. Kittel, C., 1948. On the theory of ferromagnetic resonance absorption. Phys. Rev., 73(2): 155-161.
    CrossRef    
11. Kittel, C., 1951. Ferromagnetic resonance. J. Phys. Radium, 2: 291-302.
    CrossRef    
12. Mathews, M., R. Jansen, G.R. Rijnders, J.C. Lodder and D.H.A. Blank, 2009. Magnetic oxide nanowires with strain-controlled uniaxial magnetic anisotropy direction. Phys. Rev. B, 80: 1-7.
    CrossRef    
13. Oogane, M., T. Wakitani, S. Yakata, R. Yilgin, Y. Ando, A. Sakuma and T. Miyazaki, 2006. Magnetic damping in ferromagnetic thin films. Japanese J. Appl. Phys., 45(5A): 3889-3891.
    CrossRef    
14. Pradhan, A.K., J.B. Dadson, D. Hunter, K. Zhang, S. Mohanty, E.M. Jackson, B. Lasley-Hunter, K. Lord, T.M. Williams, B.R. Sekhar, U.N. Roy, Y. Cui and A. Burger, 2006. Ferromagnetic properties of epitaxial manganite films on SrTiO3/ Si heterostructures. J. Appl. Phys., 100: 3-7.
    CrossRef    
15. Ruzmetov, D., Y. Seo, L.J. Belenky, D.M. Kim, X. Ke, S. Haipin, V. Chandrasekhar, C.B. Eom, M.S. Rzchowski and X. Pan, 2005. Epitaxial magnetic perovskite nanostructures. Adv. Mater., 17(23): 2869-2872.
    CrossRef    
16. Tovstolytkin, A., A. Pogorily, A. Vovk, D. Podyalovskii, I. Lezhnenko and A. Matviyenko, 2004. Magnetoresistance and phase separation in thin films of moderately Sr-doped manganites. J. Magn. Magn. Mater., 272: 1839-1840.
    CrossRef    

Competing interests

The authors have no competing interests.

Open Access Policy

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Copyright

The authors have no competing interests.