MOCVD selective growth of orthorhombic or hexagonal YMnO3 phase on Si(100) substrate

Influence of the orthorhombic phase content on the dielectric and magnetic properties of YMnO3

“…Another singular feature related with the different antiferromagnetic order is the spin-glass-like behavior observed for all the samples that include o-YMO phase: strong irreversibility between ZFC and FC curves as well as a peak at low temperature in the ZFC magnetization curve. The maximum at 11 K would correspond to the freezing temperature 26 . This spin-glass-like behavior has been associated to an intrinsic disorder induced by the presence of Mn 4+ ions related with the stabilization of the orthorhombic phase…”

“…The structural transition from hexagonal to orthorhombic phase gives rise to changes in the dielectric and magnetic properties, as well as different origin of ferroelectric and magnetic orders. The orthorhombic o-YMO (space group Pnma) consists of polyhedral units built up by Mn 3+ ions in the center of MnO 6 octahedra, where Mn-O bonds are relatively short and strong [25][26][27] . In this phase, both ferroelectric and magnetic orders are intimately related, as the former is induced by the latter, therefore giving rise to similar order temperatures.…”

“…It has been recently reported FM contribution for both o-YMO and h-YMO phase, although its origin is not clear. Different authors have suggested that it could be due to a non-stoichiometry of oxygen, disorder allocated at grain boundaries, or an alternative explanation could be the double-exchange interaction, which is a characteristic mechanism in perovskite oxides [4][5][6][7]23,26,52,55 . This ferromagnetic contribution observed in 1/χ curves should be also evident in the hysteresis loops.…”

Engineering of Functional Manganites Grown by MOCVD for Miniaturized Devices

“…Table 1 summarizes the most significant works reported up to now by relevant world‐class groups working in the field. A vast number of manganites systems have been synthetized, including a huge variety of lanthanum manganites (La 1– y A′ y )MnO 3 : La 1– y Sr y MnO 3 (0 ≤ y ≤ 0.65), La 0.7 Ca 0.3 MnO 3 , La 0.8 Ba 0.2 MnO 3 , La 1– y K y MnO 3 (0.05 ≤ y ≤ 0.4), La 0.82 Na 0.18 MnO 3 ; YMnO 3 , and other lanthanide manganites such as Pr 1– y Ca y MnO 3 (0.05 ≤ y ≤ 0.64), Pr 0.6 Sr 0.4 MnO 3 , LuMnO 3 , ErMnO 3 , DyMnO 3 , HoMnO 3 , TbMnO 3 , and NdMnO 3 …”

“…Several studies have focused on the effect of cation substitution on epitaxial lanthanum manganite films (La 1– y A′ y )MnO 3± δ with trivalent (e.g., Nd 3+ , Pr 3+ ), divalent (e.g., Sr 2+ , Ca 2+ , Ba 2+ ) and monovalent (e.g., Na + , K + , Ag + ) cations . On the one hand, monovalent substitution with large cations leads to a higher compressibility of the A–O bonds .…”