| Autor: |
Grigoriev MV; Laboratory of Theory and Optimization of Chemical and Technological Processes, University of Tyumen, Volodarskogo Street 6, 625003 Tyumen, Russian Federation., Ruseikina AV; Laboratory of Theory and Optimization of Chemical and Technological Processes, University of Tyumen, Volodarskogo Street 6, 625003 Tyumen, Russian Federation., Garmonov AA; Institute of Physics and Technology, University of Tyumen, Volodarskogo Street 6, 625003 Tyumen, Russian Federation., Locke RJC; Institute for Inorganic Chemistry, University of Stuttgart, D-70569 Stuttgart, Germany., Sagan F; Faculty of Chemistry, Jagiellonian University, ul. Gronostajowa 2, 30-387 Krakow, Poland., Hooper J; Faculty of Chemistry, Jagiellonian University, ul. Gronostajowa 2, 30-387 Krakow, Poland., Mitoraj MP; Faculty of Chemistry, Jagiellonian University, ul. Gronostajowa 2, 30-387 Krakow, Poland., Schleid T; Institute for Inorganic Chemistry, University of Stuttgart, D-70569 Stuttgart, Germany., Safin DA; Scientific and Educational and Innovation Center for Chemical and Pharmaceutical Technologies, Ural Federal University Named after the First President of Russia B.N. Yeltsin, Mira Street 19, 620002 Ekaterinburg, Russian Federation.; University of Tyumen, Volodarskogo Street 6, 625003 Tyumen, Russian Federation. |
| Abstrakt: |
Magnetic semiconductors EuPrCuSe 3 and EuNdCuSe 3 were obtained by using the halide flux method. Their crystal structures and magnetic properties were studied and discussed. Optical properties of the obtained selenides were studied by the means of diffuse reflectance spectroscopy, which revealed the values of 1.92/1.97 and 0.90/0.94 eV for the direct and indirect band gaps of Ln = Nd/Pr, respectively. The structural, electronic, and magnetic properties of the obtained compounds were additionally studied with spin-polarized density functional theory calculations, wherein both systems were found to be two new examples of semiconducting quaternary selenides with disperse conduction bands of Nd/Pr 5d character. The modeling showed that various magnetic orderings in the systems have subtle influences on the alignments/overlaps between the Se/Cu, Eu, and Pr/Nd bands, and that the spin-state energetics are very dependent upon the treatment of electron correlation, but a distinguishing feature in the case of ferromagnetic coupling is that the spin density on the Se atoms is maximized. Overall, the calculations are in good agreement with the experimental characterization of ferromagnetism in the bulk crystals, wherein the ferromagnetic transition occurs at temperatures of about 2.5 K for EuPrCuSe 3 and about 3 K for EuNdCuSe 3 . |
