New records of aphyllophoroid fungi (Agaricomycetes, Basidiomycota) from the Les na Vorskle area of the Belogor’e Nature Reserve (Belgorod Region, Russia)

Fifty-two species of aphyllophoroid fungi have been recorded for the first time from the Belogor’e Nature Reserve and from the Belgorod Region of Russia. An annotated list of records with data on substrate, habitat type and voucher numbers (LE, OHHI) is provided. Several rare and restrictedly distributed species in Europe are presented, viz. Hapalopilus croceus, Phellinus rimosus, Pseudomerulius aureus, Sarcoporia polyspora, and Skeletocutis odora. Two species, Gloeohypochnicium analogum and Granulobasidium vellereum, are proposed to be considered as indicators of biologically valuable broad-leaved forests in Eastern Europe.

Mssbauer study of Се2Fe17 compound in different magnetic states

Mssbauer spectra of two samples of the Ce2Fe17 compound have been analyzed and hyperfine parameters, compared. The samples were subjected to different preparation techniques and display different magnetic properties. It is established that to well fit the Mssbauer spectra of these samples, an appropriate model should be used that takes into account an additional subspectrum differing in hyperfine parameters from the subspectra employed in conventional models. It is shown that in the ferromagnetic state, the samples contain local regions with an antiferromagnetic order, the volume fraction of which, being different for two samples, increases on approaching the temperature of ferro-to-antiferromagnet transition

Magnetic properties of the non-stoichiometric TbCo2Nix alloys

The magnetic and magnetothermal properties of the non-stoichiometric TbCo2Nix (0 ≤ x ≤ 0.2) alloys were studied. It was found that the concentration dependence of the Curie temperature and magnetic moment of the 3d-sublattice have a maximum at x = 0.025. The obtained experimental magnetic properties of the TbCo2Nix alloys were discussed under assumption that the Co magnetic moment in the compounds changes with increasing x. The magnetic entropy change was determined using the temperature dependences of the magnetization and Maxwell’s thermodynamic relation. The obtained results for TbCo2Nix were compared with those for the ErCo2Mnx alloys

Mssbauer study of Се2Fe17 compound in different magnetic states

Mssbauer spectra of two samples of the Ce2Fe17 compound have been analyzed and hyperfine parameters, compared. The samples were subjected to different preparation techniques and display different magnetic properties. It is established that to well fit the Mssbauer spectra of these samples, an appropriate model should be used that takes into account an additional subspectrum differing in hyperfine parameters from the subspectra employed in conventional models. It is shown that in the ferromagnetic state, the samples contain local regions with an antiferromagnetic order, the volume fraction of which, being different for two samples, increases on approaching the temperature of ferro-to-antiferromagnet transition

Computational prediction of new magnetic materials

International audienceThe discovery of new magnetic materials is a big challenge in the field of modern materials science. We report the development of a new extension of the evolutionary algorithm USPEX, enabling the search for half-metals (materials that are metallic only in one spin channel) and hard magnetic materials. First, we enabled the simultaneous optimization of stoichiometries, crystal structures, and magnetic structures of stable phases. Second, we developed a new fitness function for half-metallic materials that can be used for predicting half-metals through an evolutionary algorithm. We used this extended technique to predict new, potentially hard magnets and rediscover known half-metals. In total, we report five promising hard magnets with high energy product (|BH|max), anisotropy field ( Ha), and magnetic hardness (κ) and a few half-metal phases in the Cr-O system. A comparison of our predictions with experimental results, including the synthesis of a newly predicted antiferromagnetic material (WMnB2), shows the robustness of our technique