Igor S. Dubenko Senior Researcher (1990) Candidate of physical and mathematical science (Ph.D. degree) (1988)

Postal address	Laboratory of Problems for Magnetism, Faculty of Physics, M.V. Lomonosov Moscow State University, Vorobjovy gory, 119992 Moscow, Russia
Telephone	+7 (095) 939 1145
FAX	+7 (095) 939 5907
E-mail	igordubenko@hotmail.com

Research interests

· Magnetism in condensed matter, Physical properties of rare earth intermetallic compounds, magnetic and electrical properties of molecular clusters and compounds with giant magnetoresistance, magneto-electric effect, superconductivity.

· Materials technology.

Main directions of the research activity

· Study of the magnetic and transport properties of R-3d intermetallic compounds with a magnetic instability of the itinerant-electron subsystem.

· Magnetism of nano-cluster materials.

· Study of the magnetoelectric properties of compounds with colossal magnetoresistance.

Main accomplishments

- Finding and investigation of first-order magnetic phase transitions in RMn₂ intermetallic compounds.

- Finding and experimental investigation of the phenomenon of temperature-induced itinerant-electron metamagnetism in intermetallic compounds of the RCo₃ series.

- Study of the characteristics of the magnetic ordering and field-induced magnetic phase transitions in multisublattice magnets with a magnetic instability (Fig. 6).

Fig. 6. Concentration dependence of the Curie temperature of the quasi-ternary compounds Tm1‑xLux(Co0.88Al0.12)2. In this system, TC rises substantially when nonmagnetic Lu replaces magnetic Tm. Such a "paradoxical" behavior of TC is explained by a sharp increase of the density of d-states near the Fermi level with increasing Lu concentration [I.S. Dubenko, R.Z. Levitin, A.S. Markosyan, JMMM 111 (1992) 146-148].

Educational and teaching work

Supervisor of Ph.D. theses: 1

Supervisor of Diploma works: 6

Total number of publications in refereed journals: 200

Some recent publications

1. I.S. Dubenko, I.Yu. Gaidukova, E. Gratz, K. Inoue, A.S. Markosyan, V.E. Rodimin, Magnetic instability of the Co sublattice in the Ho_1‑xY_xCo₃ system, Physica B 319 (2002) 21-27.

2. M. Rao, I,S, Dubenko, S. Roy, N. Ali, B.C. Dave, Matrix-assisted biomimetic assembly of ferritin core analogs in organosilica sol-gels, J. Amer. Chem. Soc. 123 (2001) 1511-1512.

3. I.S. Dubenko, I.Yu. Gaidukova, S.A. Granovsky, V. Rodimin, A.S. Markosyan, S. Roy, N. Ali, Magnetic properties of the RNi₄Mn (R = Gd, Tb, Dy, Ho, Er, Tm and Y) intermetallics, IEEE Trans. Magn. 36 (2000) 3336-3338.

4. J. Han, G.K. Marasinghe, W.J. James, M. Chen, W.B. Yelon, Ph. L'Heritier, I. Dubenko, N. Ali, Magnetic and crystallographic properties of SmMn_6‑xFe_xGe₆ intermetallics, IEEE Trans. Magn. 36 (2000) 3336-3338.

5. J. Han, G.K. Marasinghe, W.J. James, M. Chen, W.B. Yelon, I. Dubenko, N. Ali, The atomic and magnetic structure of NdMn_6‑xFe_xGe₆ solid solutions, J. Appl. Phys. 87 (2000) 5281-5283.

6. S. Roy, I.S. Dubenko, A.Yu. Ignatov, N. Ali, Study of the colossal magnetoresistance properties of the compound La_1‑xSr_xA_yMn_1‑yO₃ (A = Cr, Re), J. Phys.: Condens. Matter 12 (2000) 9465-9479.

7. M.S. Reis, I.S. Oliveira, F. Garcia, I.S. Dubenko, I.Yu. Gaidukova, A.Y. Takeuchi, A.P. Guimaraes, ⁵⁹Co nuclear magnetic resonance in the metamagnetic system Y_1‑xGd_xCo₃, J. Appl. Phys. 87 (2000) 4891-4893.

8. L. Leonard, I.S. Dubenko, N. Ali, Investigation of the ferromagnetism in RCrSb₃ (R = La, Ce, Pr, Nd), J. Alloys and Comp. 303-304 (2000) 265-269.

9. I.S. Dubenko, I.Yu. Gaidukova, A.S. Markosyan, R.Z. Levitin, F. Garsia, A.Y. Takeuchi, I.S. Oliveira, A.P. Guimaraes, Magnetization studies of the Y_1-xEr_xCo₃ intermetallics: (T_C‑x) phase diagram, J. Magn. Magn. Mater. 196-197 (1999) 674-676.

10. I.S. Dubenko, I.Yu. Gaidukova, Y. Hosokoshi, K. Inoue, A.S. Markosyan, Magnetic phase diagram and pressure effect on the magnetic properties of the Y_1‑xGd_xMn₂ intermetallic compounds, J. Phys.: Condens. Matter 11 (1999) 2937-2953.

11. I.S. Dubenko, E. Gratz, A. Lindbaum, A.S. Markosyan, S.A. Markossian, V.E. Rodimin, G. Wiesinger, Suppression of the enhanced paramagnetic thermal expansion of YMn₂ by Fe substitutions, J. Magn. Magn. Mater. 177-181 (1998) 571-572.