Synthesis of FeNi tetrataenite phase by means of chemical precipitation

Ab initio study of magnetocrystalline anisotropy, magnetostriction, and Fermi surface of L10 FeNi (tetrataenite)

The ordered L1$_0$ FeNi phase (tetrataenite) is recently considered as a promising candidate for the rare-earth free permanent magnets applications. In this work we calculate several characteristics of the L1$_0$ FeNi, where most of the results come form the fully relativistic full potential FPLO method with the generalized gradient approximation (GGA). A special attention deserves the summary of the magnetocrystalline anisotropy energies (MAE's), the full potential calculations of the anisotropy constant $K_3$, and the combined analysis of the Fermi surface and three-dimensional $\mathbf{k}$-…

Impact of chemical disorder on magnetic exchange interactions in L1$_0$-FeNi (tetrataenite)

We investigate the effect of chemical disorder on the magnetic exchange couplings and the Curie temperature ($T_{\text{c}}$) in L1$_0$-ordered FeNi using first-principles-based calculations. We use supercells to model chemical disorder, to account for the specific symmetry-broken local chemical environments around the individual atoms. We find a very strong variation of the most dominant first-nearest neighbor Fe-Fe interaction for different inequivalent Fe-Fe pairs, ranging from around 5 meV to 37 meV, compared to a coupling strength of 27 meV in the ordered state. To estimate the influence o…

Interplay between chemical order and magnetic properties in L1$_0$ FeNi (tetrataenite): A First-Principles Study

We use first-principles-based calculations to investigate the interplay between chemical order and the magnetic properties of $L1_0$ FeNi. In particular, we investigate how deviations from perfect chemical order affect the energy difference between the paramagnetic and ferromagnetic states as well as the important magneto-crystalline anisotropy energy. Our calculations demonstrate a strong effect of the magnetic order on the chemical order-disorder transition temperature, and conversely, a strong enhancement of the magnetic transition temperature by the chemical order. Most interestingly, our …

六十年后重访Néel：$\mathrm{L}1_0$ FeNi（四方镍纹石）的磁各向异性

Revisiting Néel 60 years on: the magnetic anisotropy of $\mathrm{L}1_0$ FeNi (tetrataenite)

本文通过第一性原理计算研究原子有序L10 FeNi（四方镍纹石）的磁晶各向异性，发现计算所得K1与实验一致，并揭示文献中的差异源于实验样品的纳米多晶多变体特性导致K2和K3异常增大。

Dislocation-assisted linear complexion formation driven by segregation

Atomistic simulations are used to study linear complexion formation at dislocations in a body-centered cubic Fe-Ni alloy. Driven by Ni segregation, precipitation of the metastable B2-FeNi and stable L10-FeNi phases occurs along the compression side of edge dislocations. If the Ni segregation is not intense enough to ensure precipitate growth and coalescence along the dislocation lines, linear complexions in the form of stable nanoscale precipitate arrays are observed. Critical conditions such as global composition and temperature are defined for both linear complexion formation and dislocation…