Effect of Ni Substitution on the Structural, Magnetic, and Electronic Structure Properties of Gd<sub>0.4</sub>Tb<sub>0.6</sub>(Co<sub>1−x</sub>Ni<sub>x</sub>)<sub>2</sub> Compounds
The comprehensive research of magnetic and electronic structure properties of the new class of Gd<sub>0.4</sub>Tb<sub>0.6</sub>(Co<sub>1−x</sub>Ni<sub>x</sub>)<sub>2</sub> compounds, crystallizing in the cubic Laves phase (C15), is reported...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-10-01
|
| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/23/21/13182 |
| Summary: | The comprehensive research of magnetic and electronic structure properties of the new class of Gd<sub>0.4</sub>Tb<sub>0.6</sub>(Co<sub>1−x</sub>Ni<sub>x</sub>)<sub>2</sub> compounds, crystallizing in the cubic Laves phase (C15), is reported. The magnetic study was completed with electrical resistivity and electronic structure investigations. The analysis of Arrott plots supplemented by a study of temperature dependency of Landau coefficients revealed that all compounds undergo a magnetic phase transition of the second type. Based on magnetic isotherms, magnetic entropy change (<i>ΔS<sub>M</sub></i>) was determined for many values of the magnetic field change (<i>μ</i><sub>0</sub><i>H</i>), which varied from 0.1 to 7 T. For each compound, the <i>ΔS<sub>M</sub></i> had a maximum around the Curie temperature. Both values of the |<i>ΔS<sub>M</sub><sup>max</sup></i>| and relative cooling power <i>RCP</i> parameters increased with increasing nickel content. It is shown that structural disorder upon Co/Ni substitution influences some magnetic parameters. The magnetic moment values of Co atoms determined from different methods are quantitatively consistent. From the <i>M</i>(<i>T</i>) dependency, the exchange integrals J<sub>RR</sub>, J<sub>RT</sub>, and J<sub>TT</sub> between rare-earths (R) and transition metal (T) moments were evaluated within the mean-field theory (MFT) approach. The experimental study of the electronic structure performed with the use of the X-ray photoelectron spectroscopy (XPS) was completed by calculations using the full-potential linearized augmented plane waves (FP-LAPW) method based on the density functional theory (DFT). The calculations explained experimentally observed changes in the XPS valence band spectra upon the Ni/Co substitution. |
|---|---|
| ISSN: | 1661-6596 1422-0067 |