New synthesis routes for obtaining dysprosium manganese perovskites

Carp, Oana; Patron, Luminiţa; Ianculescu, A.; Pasuk, Iuliana; Olar, Rodica

doi:10.1016/s0925-8388(02)01079-4

Cited by 25 publications

(7 citation statements)

References 20 publications

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“…Considerable care was required to synthesize homogeneous Dy-rich samples. The hexagonal phase of DyMnO 3 has been previously achieved by epitaxially stabilized crystal growth with thin films, thermal decomposition with polynuclear coordination compound precursors, and quenching methods from 1600 °C in air or at 1250 °C in argon for 3 days with sol–gel methods . Our work confirmed that synthesis in argon at high temperature tends to favor the formation of the hexagonal phase, while synthesis in oxygen tends to favor the perovskite phase .…”

Section: Resultssupporting

confidence: 78%

Synthesis and Oxygen Storage Capacities of Hexagonal Dy_1–xY_xMnO_3+δ

Remsen

Dąbrowski

2011

Chem. Mater.

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Polycrystalline samples of hexagonal P63 cm (space group No. 185) Dy1–x Y x MnO3+δ were synthesized over complete solubility ranges under reducing conditions with oxygen partial pressures of 5 ppm to air at high temperatures (1200–1400 °C). All samples displayed unusually large, reversible oxygen content excess (0 ≤ δ ≤ 0.35) at low temperatures of ∼200–400 °C under air and oxygen atmospheres in thermogravimetric measurements. During heating, stoichiometric samples showed rapid uptakes of oxygen at 200–300 °C and equally fast releases of oxygen at 275–375 °C when materials transformed back to the stoichiometric P63 cm phase. Upon slow cooling from the stoichiometric P63 cm phase, all samples displayed rapid uptakes of oxygen at 200–350 °C. Similar changes were observed as a function of oxygen partial pressure at constant temperature. Increased, reversible changes in oxygen content were also achieved by high-pressure annealings in oxygen and hydrogen reduction at 400 °C. Thermogravimetric and X-ray diffraction measurements indicate the presence of two new structural phases at δ ≈ 0.25 (Hex2) and δ ≈ 0.40 (Hex3). The thermal expansion coefficient (TEC) values of the Hex2 and P63 cm phases were determined to be (8.4–11.6) × 10–6 K–1 and (2.1–5.6) × 10–6 K–1, respectively, and the chemical expansion (CE) associated with the transition between these phases was found to be (0.82–3.48) × 10–2 mol–1.

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Section: Resultssupporting

confidence: 78%

Synthesis and Oxygen Storage Capacities of Hexagonal Dy_1–xY_xMnO_3+δ

Remsen

Dąbrowski

2011

Chem. Mater.

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“…Recent studies clearly demonstrate that the REMnO 3 with the trivalent rare earth ions having small ionic radius (A = Ho-Lu, Y, Sc), which possess stable hexagonal structures, can also be stabilized in the metastable orthorhombic GdFeO 3 -type form [53]. As an example, DyMnO 3 can be stabilized both in hexagonal as well as in orthorhombic structure [54]. Generally the hexagonal manganites exhibit two kinds of ordering phenomena: magnetic ordering around 100 K and ferroelectric ordering around 900 K [55].…”

Section: Other Perovskites and Related Materials: Remno 3 Compounds (...mentioning

confidence: 99%

The single-phase multiferroic oxides: from bulk to thin film

Prellier

Singh

Murugavel

2005

J. Phys.: Condens. Matter

622

301

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Complex perovskite oxides exhibit a rich spectrum of properties, including magnetism, ferroelectricity, strongly correlated electron behaviour, superconductivity and magnetoresistance, which have been research areas of great interest among the scientific and technological community for decades. There exist very few materials which exhibit multiple functional properties; one such class of materials is called the multiferroics. Multiferroics are interesting because they exhibit simultaneously ferromagnetic and ferroelectric polarizations and a coupling between them. Due to the nontrivial lattice coupling between the magnetic and electronic domains (the magnetoelectric effect), the magnetic polarization can be switched by applying an electric field; likewise the ferroelectric polarization can be switched by applying a magnetic field. As a consequence, multiferroics offer rich physics and novel devices concepts, which have recently become of great interest to researchers. In this review article the recent experimental status, for both the bulk single phase and the thin film form, has been presented. Current studies on the ceramic compounds in the bulk form including Bi(Fe,Mn)O3, REMnO3 andthe series of REMn2O5 single crystals (RE = rare earth) are discussed in the first section and a detailed overview on multiferroic thin films grown artificially (multilayers and nanocomposites) is presented in the second section.

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“…2,16 Introduction of small rare earth cations induces large cooperative rotations of the MnO 6/2 octahedra, which destabilize the perovskite structure and favor the hexagonal structure. The structural transition is a fluid crossover between holmium and dysprosium, and HoMnO 3 , 17 YMnO 3 , 18 and DyMnO 3 19 have been stabilized in both space groups using soft chemical methods or thin film processes. Nonetheless, all LnMnO 3 members can be formed in the orthorhombic structure using high pressure.…”

Section: Introductionmentioning

confidence: 99%