1. Detailed investigations of magnetic and magnetothermal properties of high single-crystalline samples of gadolinium, terbium and holmium in the temperature range 4,2-350 K in magnetic fields up to 10 T.
2 . The Curie temperature of ferromagnetic materials which is determined by a modified Belov-Goryaga method (Arrott plots) with a demagnetization factor taken into account strongly depends on the shape of the sample. The theoretical formula to obtain the "true" value of the Curie temperature of ferromagnets with the demagnetization factor considered has been received.
3. A theoretical estimation of the maximum possible value of the magnetocaloric effect (MCE) for bulk ferromagnetic materials at room temperature has been made. This value can be as high as 18 K/T.
4. A phenomenological universal curve for the magnetocaloric effect has been constructed. The curve can be used to predict the behavior of magnetocaloric materials in various thermodynamic conditions which are not available in the laboratory, and also for increasing the information content of the experimental data during simulation of magnetic refrigeration cycles.
5. The magnetic phase diagram of a single-crystalline Tb along the easy magnetic direction has been refined by establishing a broader than reported in the past region of the fan-like phase, by locating a tricritical point at 226 K, and by a more accurate definition of the critical fields and temperatures associated with the magnetic phases observed in Tb.
6. The magnetic phase diagram of a single-crystalline Ho in the basal plane has been refined. Together with the already known phases such as the helical AFM phase between 20 K and 128 K and the ferromagnetiс cone type structure observed below 20 K in low magnetic fields, three regions of spin-slip structures in the intervals 20-35 K, 35-42 K, and 95-110 K have been observed. In addition to the known helifan and fan phases, another phase of the “ferro+fan” type, which is located between 40-120 K and 20-80 kOe has been also detected.

1. V. Franco, A. Conde, J.M. Romero-Enrique, Y.I. Spichkin, V.I. Zverev and A.M. Tishin, Field dependence of the adiabatic temperature change in second order phase transition materials: application to Gd, Journ. of Appl. Phys, 106, 1 (2009)
2. V.I. Zverev, M.D. Kuz’min, A.M. Tishin, The maximum possible magnetocaloric ΔT-effect, Journ. of Appl. Phys, 107, 043907 (2010)
3. I.T.M. Usman, K.A. Yates, J.D. Moore, K. Morrison, V.K. Pecharsky, K.A. Gschneidner, Jr., T. Verhagen, J. Aarts, V. I. Zverev, J.W.A. Robinson, J.D.S. Witt, M.G. Blamire, L.F. Cohen, Evidence for spin mixing in holmium thin film and crystal samples, Phys. Rev. B 83, 144518 (2011)
4. V.I. Zverev, R.R. Gimaev, A.M. Tishin, Ya. Mudryk, K.A. Gschneidner, Jr., V.K. Pecharsky, The role of demagnetization factor in determining the ‘true’ value of the Curie temperature, Journ. of Magn. and Magn. Mater., 323, 2453 (2011)
5. V.I. Zverev, A.M. Tishin, Ya. Mudryk, K.A. Gschneidner, Jr., V.K. Pecharsky, A.S. Chernyshov, Magnetic and magnetothermal properties of single crystalline terbium along the easy crystallographic axis, J. Phys.: Condens. Matter 26, 066001 (2014)