Negative magnetization in the medium-entropy Pr1/3Dy1/3Ho1/3CrO3 and PrCrO3 ceramics: comparative crystal structure, optic, dielectric and magnetic properties

Abstract

In recent years, raising investigation activity in entropy-stabilized ceramic oxides has been driven by their innovative approach to designing a thermodynamically stable multi-element system, which provides a new focus on investigating complex functional materials. Especially, complex and singular physical properties of orthochromite have generated rising research in recent years. Of this family, the PrCrO3, DyCrO3, and HoCrO3 systems are particularly interesting since, below Néel temperature (TN), they present negative magnetization in the ZFC mode. Here, we have employed this approach and designed a medium-entropy (MECs) Pr1/3Dy1/3Ho1/3CrO3 (PDH) ceramic to study not only whether the magnetic characteristics prevail, but also the state of optical and dielectric properties of this new compound. In addition, the physical properties studied were compared with the single PrCrO3 (PC) compound. These compounds were synthesized through a facile combustion synthesis route. The X-ray diffraction analysis, energy-dispersive X-ray spectroscopy (EDS), and surface scanning elemental mapping reveal that a single phase is stabilized and equimolar cations are homogeneously distributed in the PDH-MECs. We found that the disorder of cations in the A-site of the structure has no significant effect on the optical transition in the visible electromagnetic region and dielectric properties with respect to the simple compound PC. In contrast, the magnetic properties are strongly affected in the MECs-PDH compound. We found that the TN is tuned through the O–Cr–O angles and below the antiferromagnetic transition. The results suggest that the negative magnetization in the ZFC mode is an intrinsic feature in these compounds since the negative ZFC susceptibility below TN predominates despite the cationic disorder. Furthermore, their negative magnetic mechanism in both the MECs-PDH and PC compounds are discussed in terms of the Γ2(FxCyGz) magnetic configuration. Graphical abstract

Formation Mechanism of Ti–Si Multi-Layer Coatings on the Surface of Ti–6Al–4V Alloy

“…The overall fit is good, and the fitted data are in good agreement with the original data. The quality of the Rietveld refinement results can also be assessed using metrics such as R wp (weighted graphical residual variance factor), R p (graphical residual variance factor), R exp (expected residual variance factor), and S 2 [21][22][23]. The expressions for R wp , R p , R exp , and S 2 are as follows [24]:…”