Related papers: Quantum Theory of Rare-Earth Magnets
Due to the resource criticality of rare-earths (RE), an alternative to the well-known Nd$_2$Fe$_{14}$B magnets with a lower amount of critical elements is required. In this work, density functional theory (DFT) calculations to investigate…
A classical spin model derived ab initio for rare-earth-based permanent magnet compounds is presented. Our target compound, NdFe$_{12}$N, is a material that goes beyond today's champion magnet compound Nd$_{2}$Fe$_{14}$B in its intrinsic…
The chapter discusses the structural and magnetic properties of equiatomic ternary RTX compounds, where R represents rare earth, T is transition metal, and X belongs to the p block elements. RTX compounds exhibit a variety of crystal…
A new class of rare-earth-free permanent magnets is proposed. The parent compound of this class is Co$_3$Mn$_2$Ge, and its discovery is the result of first principles theory combined with experimental synthesis and characterisation. The…
Prospects for light-rare-earth-based permanent magnet compound R$_{2}$Fe$_{14}$B (R=La$_{1-x}$Ce$_{x}$ with $0 \le x\le 1$) are inspected from first principles referring to the latest experimental data. Ce-rich 2:14:1 compounds come with…
The RE$_{5}$Pt$_2$In$_4$ (RE = Gd-Tm) rare earth compounds have been investigated by means of X-ray diffraction (XRD) as well as by DC and AC magnetometric measurements. The compounds crystallize in an orthorhombic crystal structure of the…
Atomic-scale computational modeling of technologically relevant permanent magnetic materials faces two key challenges. First, a material's magnetic properties depend sensitively on temperature, so the calculations must account for thermally…
We present a theory of the magnetic rare-earth nickel boride-carbides (RENi$_2$B$_2$C, RE=Ho, Er, Tm). Large total angular momentum allows one to employ semiclassical approximation and reduce the problem to the four-positional clock model.…
The development of permanent magnets containing less or no rare-earth elements is linked to profound knowledge of the coercivity mechanism. Prerequisites for a promising permanent magnet material are a high spontaneous magnetization and a…
We present a data set of calculated Curie temperatures for the main-phase compounds of rare-earth permanent magnets. We employ ab initio electronic structure calculations for the itinerant ferromagnetism and an effective spin model for the…
This research aims to identify an alternative solution for the Nd$_2$Fe$_{14}$B magnet in light of the scarcity of rare earth (RE) resources. The investigation uses density functional theory (DFT) calculations to assess the effect of…
New hard magnetic materials with zero or low rare earth content are in demand due to the high prices of the rare earth metals. Among the candidates for such materials, we consider MnB, FeB and their alloys, because previous experiments…
In rare-earth permanent magnets (REPM's), trade-off's between intrinsic magnetic properties are often encountered. A recent example is SmFe$_{12}$ where excellent magnetic properties can be achieved at the sacrifice of bulk structure…
We report muon spin rotation ($\mu$SR) and neutron diffraction on the rare-earth based magnets (Mo$_{2/3}$RE$_{1/3}$)$_2$AlC, also predicted as parent materials for 2D derivatives, where RE = Nd, Gd (only ($\mu$SR), Tb, Dy, Ho and Er. By…
Multiscale simulation is a key research tool for the quest for new permanent magnets. Starting with first principles methods, a sequence of simulation methods can be applied to calculate the maximum possible coercive field and expected…
RRhGe (R=Tb, Dy, Er, Tm) compounds have been studied by a number of experimental probes and theoretical ab initio calculations. These compounds show very interesting magnetic and electrical properties. All the compounds are…
We describe an ab-initio disordered local moment theory for long period magnetic phases and investigate the temperature and magnetic field dependence of the magnetic states in the heavy rare earth elements (HRE), namely paramagnetic,…
The magnetocaloric effect (MCE) in many rare earth (RE) based intermetallic compounds has been extensively investigated during last two decades, not only due to their potential applications for magnetic refrigeration but also for better…
A first-principles approach combining density functional and dynamical mean-field theories in conjunction with a quasi-atomic approximation for the strongly localized 4$f$ shell is applied to Nd$_{2}$Fe$_{14}$B-based hard magnets in order…
Permanent magnets are integral components in many of the modern technologies that are critical for the transition to a sustainable society. However, most of the high-performance (BHmax > 100 kJ/m3) permanent magnets that are currently…