The system SrMnO3−x

Negas, T.; Roth, Robert

doi:10.1016/0022-4596(70)90123-4

Cited by 234 publications

(163 citation statements)

References 9 publications

Supporting

Mentioning

151

Contrasting

Unclassified

Order By: Relevance

“…The crystal structures at ambient conditions Le Bail refinement of PXRD on 4H-SrMnO 3 at ambient conditions yielded the refined lattice parameters a = 5.45088(10) Å and c = 9.0851(3) Å, in good agreement with the experimental values found by others 9,13,14,30,32,33 . The refined model can be found in the SM, part 1 15 .…”

Section: Resultssupporting

confidence: 82%

“…The value of a 0 for the re-oxidized sample is not in perfect agreement with others 13,14,34 indicating that complete re-oxidization might not have been achieved. This is noteworthy as the a 0 obtained from this measurement lies outside the trend of the full EoS mapping of the 3C-phase, which used a fraction of the same sample.…”

Section: Resultsmentioning

confidence: 49%

“…It is concluded that the sample was reduced inside the DAC as a result of the high temperate. Indeed, it is this high temperature reduction which was observed at ambient pressure and 1773 K by Negas & Roth and which was used to synthesize 3C-SrMnO 3 in the first place 13 . It is also possible that the inert neon pressure medium has an effect.…”

Section: H-to 3c-srmnomentioning

confidence: 93%

“…This would serve to move the stability border of 4H upwards in pressure as one moves along the axis of x in SrMnO 3-x . At high temperatures, the entropy of the 3C structure must be greater than that of the 4H structure, evidenced by the fact that the 3C structure was observed in the experiments of Negas & Roth 13 for the stoichiometry x > 0.279. Further calculations would have to be performed in order to establish whether the 6H stability field is expanded or contracted by movement along the third dimension.…”

Section: E Towards a Pt Phase Diagrammentioning

confidence: 96%

See 3 more Smart Citations

Phase stability of theSrMnO3hexagonal perovskite system at high pressure and temperature

et al. 2014

View full text Add to dashboard Cite

SrMnO 3 is a perovskite compound which, unlike most perovskites, can be synthesized in three different but closely related polymorphs. In this paper, the first experimental equation of state of the 6H polymorphs is reported. The experimentally determined bulk modulus of SrMnO 3 increases from 115.6(11) GPa in the 4H polymorph to 143.7(17) GPa in the 6H polymorph, while DFT calculations predict a further increase to 172.5(4) GPa in the 3C polymorph. The first in situ observations of transformations between the three known polymorphs, under high pressure and high temperature conditions are also reported. The results are compared with extensive DFT calculations and literature, and it is demonstrated that the 6H polymorph is the thermodynamically stable phase between 5.9(3) and 18.1(2) GPa at zero kelvin. The effect of possible oxygen sub-stoichiometry is also explored, used DFT. Finally, the findings are combined with the existing knowledge of the phase behavior in this system to outline where further knowledge needs to be collected before a PT phase diagram can be constructed for this system. I. INTRODUCTIONInorganic compounds with the formula ABX 3 very often crystallize in the well-known perovskite structure, or distorted derivatives thereof. In the ideal cubic structure, the unit cell can be described by an AX 3 cubic close-packed layer, with B ions in the octahedral holes that are surrounded only by X anions. The packing sequence is abc, a being the first hexagonal layer, b the second layer that covers half the holes in a, and c the third placed on top of b to cover the other half. This class of materials covers a wide range of technologically relevant compounds that can display piezoelectric 1 , ferroelectric 2 , (anti)ferromagnetic 3 , catalytic 4 , semiconducting 5 , metallic 6 or insulating 6 behavior. Due to the widespread use of materials with this structure, it is worthwhile trying to gain a deeper insight into the factors governing phase stability in this type of system.

show abstract

Section: Resultssupporting

confidence: 82%

Section: Resultsmentioning

confidence: 49%

Section: H-to 3c-srmnomentioning

confidence: 93%

Section: E Towards a Pt Phase Diagrammentioning

confidence: 96%

See 2 more Smart Citations

Phase stability of theSrMnO3hexagonal perovskite system at high pressure and temperature

et al. 2014

View full text Add to dashboard Cite

show abstract

“…1 In their study, at temperatures below 1308 K, SrMnO 3 had a four-layered hexagonal 4H structure in which a 0.5449 nm and c 0.9078 nm; within the range from 1308 K to 1673 K, SrMnO 3 evolved oxygen and oxygen-deficient SrMnO 3 d showed the 4H structure; and above 1673 K, cubic perovskite-type SrMnO 3 d was obtained by rapid quenching of a sample heated above 1673 K. According to Mizutani et al, 2 the synthesis temperature of cubic perovskite-type SrMnO 3 d was lowered by heating in a flow of CO 2 gas, and the oxygen deficiency of SrMnO 3 d vanished with annealing at 573-773 K in air for several hours. In their study, cubic perovskite-type SrMnO 3 had a lattice constant of a 0.38057d0.00003 nm, in which MnO 6 octahedra shared corners with each other and the Mn 4 -O-Mn 4 angle was 180c .…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Four-Layered Hexagonal (Sr1-xBax)MnO3 (0.0.LEQ.x.LEQ.0.5)

秀樹

明彦

眞彦

et al. 2007

J. Ceram. Soc. Japan

View full text Add to dashboard Cite

Structural, Spectroscopic, Magnetic and Thermal Properties in the [SrM(C3H2O4)2(H2O)5]· 2 H2O (M = Mn, Fe, Co, Ni) System: Precursors of SrMO3–x Mixed Oxides

Insausti

Lezama

Pizarro

et al. 1999

Eur. J. Inorg. Chem.

View full text Add to dashboard Cite

The [SrM(C3H2O4)2(H2O)7] (M = Mn, Fe, Co, Ni) compounds have been prepared and characterised by chemical analysis and X‐ray diffraction. The crystal structure of [SrCo(C3H2O4)2(H2O)5] · 2 H2O has been solved [monoclinic, P21/c, Z = 4, a = 6.880(1), b = 14.360(2), c = 15.800(2) Å. β = 101.69(1)°]. The compound exhibits a three‐dimensional chain/snake structure consisting of –CoO6–[SrO7]∞–CoO6– repeating units parallel to the [0 1 1] and [0 –1 1] directions. UV/Vis data are consistent with the cations being in a high‐spin octahedral symmetry. Magnetic measurements show antiferromagnetic interactions for all compounds with approximate θ values of –0.5 K, except for the cobalt compound (–24.5 K) where the decrease of the χmT curve can also be attributed to the spin‐orbit coupling. Thermal analyses performed in air and under nitrogen show three consecutive steps: dehydration, ligand pyrolysis, and inorganic residue evolution. Thermal treatments in tubular furnaces were performed in order to obtain pure SrMO3–x phases. In all cases the oxides are nonstoichiometric and oxygen‐deficient with structures related to that of perovskite. Lower temperatures and reaction times than those given in the literature have been used when using the ceramic method. These “soft” treatments gave rise to homogeneous particles of small grain size.

show abstract

The system SrMnO3−x

Cited by 234 publications

References 9 publications

Phase stability of theSrMnO3hexagonal perovskite system at high pressure and temperature

Phase stability of theSrMnO3hexagonal perovskite system at high pressure and temperature

Synthesis and Characterization of Four-Layered Hexagonal (Sr1-xBax)MnO3 (0.0.LEQ.x.LEQ.0.5)

Structural, Spectroscopic, Magnetic and Thermal Properties in the [SrM(C3H2O4)2(H2O)5]· 2 H2O (M = Mn, Fe, Co, Ni) System: Precursors of SrMO3–x Mixed Oxides

Contact Info

Product

Resources

About