Effect of Ni-doping on structural, magnetic and magnetocaloric properties of La 0.6 Pr 0.1 Ba 0.3 Mn 1− x Ni x O 3 nanocrystalline manganites synthesized by Pechini sol–gel method

Effect of Ni-doping on critical behavior of La0.6Pr0.1Ba0.3Mn1−xNixO3 nanocrystalline manganites

“…[23][24][25][26] On the other hand, we can attribute the increase of the critical exponent  to the reduction of the average grain size which decreases as Ni-content increases [11]. This may be explained, as we mentioned in our previous work [11], to the presence of a nonmagnetic surface layer (which destabilizes the magnetic order) that is more important as the average grain size decreases. This surface layer has spins that are aligned in random directions due to randomness of the local anisotropy field [28].…”

“…Recently, we have investigated in our previous work [11] shown by several studies [11][12][13][14], the Mn ions are ferromagnetically coupled through the double exchange interaction but the coupling between Mn and Ni obeys the antiferromagnetic super exchange mechanism. These two mechanisms compete with each other in perovskite manganites [13].…”

“…presented in Ref [11]. (the T C estimation can be obtained, from the M(T) curves, by determining the minimum value of dM/dT versus T curves).…”

Microstructural analysis, magnetic properties, magnetocaloric effect, and critical behaviors of Ni0.6Cd0.2Cu0.2Fe2O4 ferrites prepared using the sol–gel method under different sintering temperatures

“…In recent years, large MCEs have been found in other materials, such as perovskite manganites ABO 3 (ref. [4][5][6][7][8] and spinel ferrites AFe 2 O 4 , [9][10][11][12][13][14] which have attracted increasing attention in MR research. The main advantages of these materials over Gd and GdSiGe alloys 15 are low coercive forces, nonactive chemical properties (no oxidation), low costs, and high electric resistance (minimum Eddy current loss).…”

Effect of Fe Substitution on the Physical Properties of La0.62Er0.05Ba0.33Mn1−xFexO3(x = 0.00, 0.05 and 0.15)

“…In terms of the crucial role of Mn site, it would be interesting and worthwhile to study the effects of Mn-site element substitution, which may provide clues for exploring novel MCE materials and concerning the mechanism of MCE. Within this framework, the effect of substituting trivalent ions such as Fe, Ni and Sc for Mn 3+ ions in the B site on the ferromagnetic properties of these manganites has been studied [22][23][24][25]. It was experimentally found that any modification on the exchange interaction causes the pair-braking effect associated with a drastic reduction in Curie temperature T C .…”