Stability of metallic, magnetic and electronic states in NaZn13-type La(FexSi1−x)13 magnetocaloric compounds

Low-temperature specific heat in hydrogenated and Mn-dopedLa(Fe,Si)13

“…The first calculations were made by Kuz'min and Richter [9] on LaFe12Si, showing that the free energy had several shallow minima and maxima as a function of the magnetisation. Fujita and Yako [10] extended this work to study the influence of Si site occupancy as a function of Si concentration, and Gercsi et al have developed it further to look at interstitials [11]. Most recently Gruner et al [13], focused on understanding how the vibrational density of states is influenced by the magnetoelastic coupling across the transition.…”

“…The variation in Si site occupancy could affect the absolute value of D. As there are two Fe sites, and in principle the Si site occupancy might depend on sample processing strategy, Fujita and Yako discuss whether there is preferential occupancy, calculating whether one site is more energetically favourable [10]. It is likely that site disorder is a contributing factor to the discrepancies between reported measurements.…”

“…In recent times there have been new efforts to examine the metamagnetic transition in La(Fe,Si)13 in terms of the itinerant electron metamagnetism (IEM). First principle calculations based on density functional theory (DFT) have been used to study the variation of Si content [9,10] and the effect of interstitial doping [11] and transition metal substitution [12] on the electronic structure and nature of the magnetic interaction. Most recent of these is a study of the thermodynamics of the transition with a particular focus on the pronounced magnetoelastic softening despite the large volume decrease at the transition [13].…”

“…Significant theoretical progress has been made to describe the electronic properties and the influence of substitution and interstitial occupancy [9][10][11][12][13] in La(FeSi)13, but detailed comparison with experiment is lacking. In order to make better comparison to theory we determine the behaviour of the low temperature specific heat and extract , α and D in a series of samples of LaFexMnySiz with and without hydrogen.…”

Magnetic Properties and Magnetocaloric Effect in Layered NdMn1.9V0.1Si2

“…The study of the magnetocaloric effect (MCE) has become an interesting area of research in the field of magnetic materials, with increasing prospects as the basis of magnetic cooling to replace conventional refrigeration [1][2][3][4]. Magnetic materials with large MCE have been extensively studied experimentally and theoretically; the first order magnetic phase transition is accompanied by large thermal and field hysteresis in the temperature and magnetic field dependent magnetization.…”