Comprehensive analysis on the effect of ionic size and size disorder parameter in high entropy stabilized ferromagnetic manganite perovskite

A remarkable high entropy effect on the magnetic behaviour of quadruple perovskites

“…peaks are ascribed to the satellite peaks. 16 The high-resolution scans of Cu 2p spectra showed 4 strong peaks for all the samples, the peak at 933.50–934.60 eV belongs to Cu 2p 3/2 , the two peaks at 940.90–943.950 eV and 961.40–962.90 eV belong to satellite peaks and the peak at 952.70–954.90 eV is ascribed to Cu 2p 1/2 . The deconvolution of Cu 2p 3/2 and Cu 2p 1/2 resulted in different peaks, of which the lower B.E peaks are attributed to the Cu 2+ occupying the octahedral position, i.e.…”

“…peaks are ascribed to the satellite peaks. 16 The high-resolution scans of Cu 2p spectra showed 4 strong peaks for all the samples, the peak at 933. 50 ).…”

“…This T C value is much lower than that of the conventional counterpart LaCu 3 Ti 2 Mn 2 O 12 with a T C value of ∼200 K. 47 The large drop in T C in high entropy oxides has been attributed to the disordering in bond lengths and bond angles associated with the multiple A-site cation and local lattice distortion. 16,17 This gigantic drop in T C for (La 0.2 Pr 0.2 Nd 0.2 Sm 0.2 Y 0.2 )Cu 3 Ti 2 Mn 2 O 12 suggests the significant weakening of the superexchange interaction Cu 2+ ↑–O–Mn 3+/4+ ↓–O–Cu 2+ ↑ in the structural framework of multiple A-site cations of varied size and hence associated localized lattice distortion which hampers the smooth exchange interaction. Here, it is worth to compare the low temperature magnetic ground state of the conventional and high entropy phases.…”

“…This fascinating class of materials are projected to be highly promising materials due to their unprecedented properties and phenomena. [7][8][9][10][11][12][13][14][15][16][17] Accommodation of Cu and Zn in the rock salt structure (Co 0.2 Cu 0.2 Mg 0.2 Ni 0.2 Zn 0.2 )O requires enthalpic penalties. This is due to the fact that unlike the rock salt structure of (Mg/Co/Ni)O, CuO and ZnO have tenorite and wurtzite structures, respectively.…”

High-entropy rare earth materials: synthesis, application and outlook

“…In another work about the promising electro-magnetic properties in HE-RE manganites, a set of HE manganites, denoted as (5A 0.2 )MnO 3 , was synthesized with variations in the average ionic radius ( r A ) and cationic size disorder ( σ 2 ) at the A-site. 152 The high-entropy oxides exhibited a wide range of T C , varying from 85 to 273 K, which was dependent on the average A-site ionic radius. Contrary to the anticipated linear behavior, the variation in T C with r A in the entire series of high-entropy manganites followed the opposite trends to the variation in σ 2 with r A .…”