The surface magnetic anisotropy of the CoFe2O4 nanoparticles with giant low-temperature hysteresis - K. A. Mozul; L. P. Olkhovik; Z. I. Sizova; A. N. Bludov; V. A. Pashchenko; V. N. Baumer; V. V. Vashchenko; M. A. Kolosov; A. P. Kryshtal; M. F. Prodanov (Low Temperature Physics, 2013)