Improving room temperature magnetoresistance in derivatives of ferrimagnetic CaCu3Mn4O12 perovskite

Ti-rich double perovskites LnCu3−yTi2−xMn2+x+yO12: ferrimagnetism and magnetoresistance up to room temperature

“…[4][5][6][7][8][9][10][11] In contrast, in the present titanomanganites, the fact that the evolution of the MR maximum follows the evolution of T C , like in many single perovskite manganites shows that the observed MR effect is representative of the bulk. Differently from high pressure synthesized double perovskite manganites, which exhibit a sharp increase in the MR at low elds as H increases, 4,20 we do not observe any predominant low eld MR effect. Thus, the extrinsic MR, due to grain boundaries effects in our polycrystalline Ti-rich manganites can be considered as very weak and negligible.…”

“…[7][8][9][10][11]. Indeed, for those HP manganites the different authors showed that MR increases continuously as the temperature decreases down to 5 K. 4,20 They ascribed the origin of MR in those (Ln/Ca)Cu 3Àx Mn 4+x O 12 compounds to spin polarized tunnelling or spin dependent scattering effect at grain boundaries. [4][5][6][7][8][9][10][11] In contrast, in the present titanomanganites, the fact that the evolution of the MR maximum follows the evolution of T C , like in many single perovskite manganites shows that the observed MR effect is representative of the bulk.…”

Peculiar Magnetic Behavior of the TbCu3Mn4O12 Complex Perovskite

“…In this system, Ca cations can be replaced by rare earths in the RCu 3 Mn 4 O 12 (R = rare earths) series, implying an electron doping effect that affects the magnetic and transport properties, as demonstrated for R = La, Ce, Nd, and Th. , In the case of R = La 8 we have described an excellent low-field MR magnitude at RT, comparable to the best values known for bulk magnetoresistance materials at RT.…”

Preparation, Crystal Structure, and Magnetotransport Properties of the New CdCu3Mn4O12 Perovskite: A Comparison with Density Functional Theory Calculations

“…By taking into account the derivative of the magnetic susceptibility (upper curve in Figure ), there are two different inflection points, arising from two consecutive Curie temperatures ( T C ). The main phase, CdCu 3 Mn 4 O 12 , has a magnetic ordering temperature of 347 K, while for the secondary phase (CdCu 2.4 Mn 4.6 O 12 ), the observed T C is 264 K. It has been previously reported − in related complex perovskites that T C decreases as Mn atoms are incorporated into the Cu positions. Magnetic order for the main phase occurs at a slightly lower temperature than for the parent CaCu 3 Mn 4 O 12 compound ( T C = 355 K)…”