1. B.D. Cullity and C.D. Graham: Introduction to Magnetic Materials, 2nd ed. (IEEE/Wiley, Hoboken, NJ, 2009).
2. N.A. Spaldin: Magnetic Materials: Fundamentals and Applications, 2nd ed. (Cambridge University Press, Cambridge; New York, 2011).
3. R.C. Rai, S. Wilser, M. Guminiak, B. Cai, and M.L. Nakarmi: Optical and electronic properties of NiFe2O4 and CoFe2O4 thin films. Appl. Phys. a-Mater 106, 207 (2012).
4. M. Srivastava, A.K. Ojha, S. Chaubey, and A. Materny: Synthesis and optical characterization of nanocrystalline NiFe2O4 structures. J. Alloy. Compd. 481, 515 (2009).
5. P. Zhao, Z.L. Zhao, D. Hunter, R. Suchoski, C. Gao, S. Mathews, M. Wuttig, and I. Takeuchi: Fabrication and characterization of all-thin-film magnetoelectric sensors. Appl. Phys. Lett. 94, 24 (2009).