Comprehensive study of the magnetic phase transitions in Tb3Co combining thermal, magnetic and neutron diffraction measurements
| Autor: | N. V. Baranov, Alberto Oleaga, Matthias Frontzek, Agustín Salazar, A. F. Gubkin, A. Herrero |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Phase transition
Materials science SPIN-ORDERING COBALT ALLOYS MAGNETOCALORIC EFFECTS Neutron diffraction NEUTRON DIFFRACTION VECTOR SPACES 02 engineering and technology MAGNETOCALORIC EFFECT 01 natural sciences NEUTRONS Paramagnetism FERROMAGNETISM ANTIFERROMAGNETISM FERROMAGNETIC MATERIALS 0103 physical sciences Materials Chemistry Antiferromagnetism IRON COMPOUNDS THERMAL DIFFUSIVITY SINGLE-CRYSTAL NEUTRON DIFFRACTION TEMPERATURE 010302 applied physics Condensed matter physics Magnetic moment TB3CO Mechanical Engineering BINARY ALLOYS SECOND-ORDER PHASE TRANSITION Metals and Alloys CRYSTAL SYMMETRY General Chemistry SINGLE CRYSTALS 021001 nanoscience & nanotechnology MAGNETIC PHASE TRANSITIONS Magnetic field FERROMAGNETIC STRUCTURES NEUTRON DIFFRACTION MEASUREMENTS Ferromagnetism MAGNETIC MOMENTS Mechanics of Materials Condensed Matter::Strongly Correlated Electrons CRITICAL BEHAVIOR 0210 nano-technology Critical exponent SPIN ORDER TERBIUM ALLOYS |
| Zdroj: | Intermet Intermetallics |
| Popis: | A comprehensive study of the magnetic phase transitions in Tb3Co has been undertaken combining different techniques. Using single crystal neutron diffraction in the paramagnetic state a weak crystal structure distortion from the room temperature orthorhombic structure of the Fe3C type described with the Pnma space group toward structure with lower symmetry has been observed with cooling below 100 K. At 81 K there is a second order phase transition to an antiferromagnetic incommensurate phase with the propagation vector k = (0.155, 0, 0). As derived from thermal diffusivity measurements, the critical exponents for this transition are very close to the 3D-Heisenberg universality class, proving that the magnetic interactions are short-range but with a deviation from perfect isotropy due to crystal field effects. At T2 ≈ 70 K there is another magnetic phase transition to a ferromagnetic state whose character is shown to be weakly first order. The low temperature magnetic state has a non-coplanar ferromagnetic structure with strong ferromagnetic components of Tb magnetic moments along the crystallographic c-axis. The application of an external magnetic field B = 2 T along the c crystallographic axis suppresses the incommensurate antiferromagnetic phase and gives rise to the ferromagnetic phase. The magnetic entropy peak change as well as the refrigerant capacity indicate that Tb3Co is a competitive magnetocaloric material in this temperature range. © 2019 Elsevier Ltd |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|