On the structure and magnetic properties of the series RBa2Fe3O8+x (R=La,Nd,Sm,Gd)

Nanoscale Ordering in Oxygen Deficient Quintuple Perovskite Sm2-εBa3+εFe5O15-δ: Implication for Magnetism and Oxygen Stoichiometry

“…= 10 -12.44 -10 -29.4 bar), whereas the synthesis of SmBa 2 Fe 3 O 8-δ required an oxygen flow at 1000°C[10][11][12]. In contrast, we show here that a single phase perovskite can be synthesized in air for the nominal composition corresponding to the formula Sm 0.375 Ba 0.625 FeO 3-y (x = 0.625).…”

“…In oxygen deficient perovskites, the ordering of these cations in the form of layers is at the origin of attractive magnetic and magnetoresistance properties, as for example in LnBaCo 2 O 5+δ "112" cobaltites (see for a review ref [9]). In this respect, iron oxygen deficient perovskites, such as LnBaFe 3 O 8+δ [6,[10][11] and LnBaFe 2 O 5+δ [12][13][14][15], isostructural to the cobalt layered perovskites, have also attracted attention as examples of compounds with double ordering in the cationic sites Ba 2+ /Ln 3+ and in the anionic sites between oxygen and vacancies in the form of layers. Like the cobaltites, these layered ferrites exhibit attractive physical properties such as magnetoresistance and Verwey transition under oxygen loading.…”

Quintuple perovskites Ln2Ba3Fe5−xCoxO15−δ(Ln = Sm, Eu): nanoscale ordering and unconventional magnetism

“…1 and 2), and LnBa 2 Fe 3 O 8+d that were investigated for their magnetic properties. [3][4][5] The 1 : 1 ordering discovered for YBaFeCuO 5 6 was observed in the double perovskites LnBaCo 2 O 5 and LnBaCo 2 O 5+d that were explored by many authors for their exceptional magnetic and magneto-transport properties (see for a review ref. 7) and in the magnetic ferrites LnBaFe 2 O 5+d .…”

Exceptional Layered Ordering of Cobalt and Iron in Perovskites

“…Moreover, this large family has been studied for its attractive properties, ranging from oxygen storage in view of the realization of solid oxide fuel cell cathodes (SOFC) [1][2][3][4][5][6] , to magnetic and magnetoresistance properties 7 . The layered perovkites of the Ln-Ba-Co-O and Ln-Ba-Fe-O systems are mainly represented by two classes, the double perovskites LnBaCo2O5+δ and LnBaFe2O5+δ [37][38][39][40][41][42][43] , called "112" and the triple perovskites LnBa2Fe3O8+δ, called "123" [44][45][46][47][48] . These oxides are characterized by a regular ordering of the layers of rare earth (or lanthanide Ln) and barium cations, which originates from the size difference between these two sorts of cations.…”