Crystal structures and phase transition in (Sr0.8Ce0.2)(Mn1−yCoy)O3(y= 0 and 0.2): the influence of Jahn–Teller distortion

2009 ◽  
Vol 21 (12) ◽  
pp. 124218 ◽  
Author(s):  
Zhaoming Zhang ◽  
Christopher J Howard ◽  
Brendan J Kennedy ◽  
Motohide Matsuda ◽  
Michihiro Miyake
Keyword(s):  
Phase Transition ◽  
Crystal Structures ◽  
Teller Distortion ◽  
Jahn Teller ◽  
Jahn Teller Distortion

Phase Transition of LiMn2O4 Spinel and its Application for Lithium Ion Secondary Battery

1997 ◽  
Vol 496 ◽  
Author(s):  
Junji Tabuchi ◽  
Tatsuji Numata ◽  
Yuichi Shimakawa ◽  
Masato Shirakata
Keyword(s):  
Phase Transition ◽  
Lithium Ion ◽  
Electrochemical Characteristics ◽  
Teller Distortion ◽  
Limn2o4 Spinel ◽  
Structure Changes ◽  
Jahn Teller ◽  
Initial Charge ◽  
Lower Temperature ◽  
Jahn Teller Distortion

ABSTRACTLiMn2O4 has a phase transition at room temperature, which is caused by Jahn-Teller distortion. DC resistivity of LiMn2O4 shows an anomaly at the transition temperature, while no such anomaly is observed in samples with excess lithium. X-ray diffraction patterns of LiMn2O4reveal that the crystal structure changes from cubic at higher temperature to orthorombic, as a first approximation, at lower temperature. However, no differences in initial charge-discharge curve are observed, which means that the Jahn-Teller distortion has no effect on electrochemical characteristics. The authors have succeeded in mass-producing lithium ion secondary batteries with a manganese spinel cathode.

Structure of the clinopyroxene-type compound CaCuGe2O6 between 15 and 800 K

2005 ◽  
Vol 61 (4) ◽  
pp. 367-380 ◽  
Author(s):  
Günther J. Redhammer ◽  
Gerold Tippelt ◽  
Michael Merz ◽  
Georg Roth ◽  
Werner Treutmann ◽  
...  
Keyword(s):  
Phase Transition ◽  
Magnetic Susceptibility ◽  
Magnetic Phase ◽  
Metal Layer ◽  
Lattice Parameters ◽  
Zigzag Chain ◽  
Two Dimensional ◽  
Teller Distortion ◽  
Jahn Teller ◽  
Jahn Teller Distortion

CaCuGe2O6 shows a strongly distorted clinopyroxene-type structure with P21/c symmetry at 298 K. The Cu2+ ion at the M1 site is coordinated by six O atoms forming an octahedron, which deviates significantly from ideal geometry. Individual M1 sites are connected via common edges to form an infinite zigzag chain parallel to the crystallographic c axis. The Ca2+ ion at M2 shows a sevenfold coordination. M2 sites are connected to the M1 chain via three common edges, thereby forming a metal layer within the bc plane. Besides the strong Jahn–Teller distortion of the Cu site, the structure of the title compound differs from `normal' clinopyroxenes by a distortion of alternate layers of Ge sites. While the Ge(A) site is fourfold coordinated by O atoms, forming infinite chains of corner-sharing chains parallel to the c axis, the Ge(B) site exhibits a fivefold coordination, thereby forming a true two-dimensional layer of edge-sharing GeO5 bipyramids. Decreasing the temperature causes a magnetic phase transition at 40 K, as monitored by a broad maximum in the magnetic susceptibility and by discontinuities in the lattice parameters. Increasing the temperature causes variations in bond lengths, edge lengths and bond angles. Most prominent is the increase of one bond length of the Ge(B) site and the increase of the tetrahedral bridging angle of the Ge(A) site. At 660 K a crystallographic phase transition is observed where the symmetry changes from P21/c to C2/c. The transition is accompanied by large changes in the lattice parameters which are indicative of distinct topological changes of several structural building units. The high-temperature C2/c structure is similar to that of the germanate clinopyroxene CaMgGe2O6.

scholarly journals Die Jahn-Teller-Verzerrung in den Kristallstrukturen der Dinatrium-Tetrafluorometallate Na2CuF4 und Na2CrF4 / The Jahn-Teller Distortion in the Crystal Structures of the Disodium-Tetrafluorometallates Na2CuF4 and Na2CrF4

1989 ◽  
Vol 44 (7) ◽  
pp. 715-720 ◽  
Author(s):  
Dietrich Babel ◽  
Michael Otto
Keyword(s):  
Crystal Structures ◽  
Chain Structure ◽  
Teller Distortion ◽  
Space Group ◽  
X Ray ◽  
Edge Sharing Octahedra ◽  
Jahn Teller ◽  
A Chain ◽  
Jahn Teller Distortion ◽  
Ray Methods

The crystal structures of the isotypic monoclinic fluorides Na2CuF4 (a = 326.7(1), b = 937.0(2), c = 561.2(1) pm, β = 92.49(1)°; V = 171.63 x10-30 m3) and Na2CrF4 (a = 334.8(1), b = 954.9(2), c = 566.5(3) pm, β = 92.85(3)°; V = 180.89 × 10-30 m3) have been redetermined by single crystal X-ray methods. The compounds are Jahn-Teller distorted variants of the orthorhombic Sr2PbO4type (space group Pbam) and crystallize with Z = 2 in space group P21/c, a subgroup of Pbam. They form a chain structure of edge-sharing octahedra which are strongly elongated. The following distances were obtained: Cu-F = 190.4/193.8/235,7(2) pm and Cr-F = 199.1/199.7/241.7(4) pm. The geometry is compared to that of the corresponding distorted rutile type difluorides; relations to further compounds are discussed.

The role of Jahn–Teller distortion in insulator to semiconductor phase transition in organic–inorganic hybrid compound (p-chloroanilinium)2CuCl4at high pressure

2015 ◽  
Vol 17 (48) ◽  
pp. 32204-32210 ◽  
Author(s):  
Pallavi Ghalsasi ◽  
Nandini Garg ◽  
M. N. Deo ◽  
Alka Garg ◽  
Hemant Mande ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Hybrid Compound ◽  
Teller Distortion ◽  
Inorganic Hybrid ◽  
Jahn Teller ◽  
Jahn Teller Distortion

The captions for pressure values are not centered below each micrograph.

Die Kristallstrukturen von Na2CoFeF7 und einer zweiten Modifikation von Na2CuFeF7: Eine weitere Weberit-Variante / The Crystal Structures of Na2CoFeF7 and a Second Modification of Na2CuFeF7: Another Weberite Variant

1992 ◽  
Vol 47 (5) ◽  
pp. 685-692 ◽  
Author(s):  
Matthias Welsch ◽  
Dietrich Babel
Keyword(s):  
Crystal Structures ◽  
The Other ◽  
Intermediate Type ◽  
Teller Distortion ◽  
Space Group ◽  
Jahn Teller ◽  
Structural Relations ◽  
Jahn Teller Distortion

The monoclinic weberites Na2CoFeF7 (a = 1262.2(10), b = 736.0(4), c = 2451.6(20) pm, β = 99.71(5)°) and a second modification of Na2CuFeF7 (a = 1244.4(2), b = 734.3(1), c = 2467.2(5) pm, β = 99.27(3)°), crystallize isotypically in space group C 2/c, Ζ = 16. The structure is an intermediate type between orthorhombic and trigonal weberites, characterized by pairs ofparallel chains of octahedra [MF4F2/2]3- (M = Co, Cu) which run in turn along [110] and [110]. The average distances are Fe-F = 192 pm in the [FeF63- octahedra of both compounds. Considerable splitting of distances occurs in the [CoF6- octahedra (av. Co-F = 201 pm), and by Jahn-Teller distortion even more in those of [CuFJ4- (av. Cu-F = 199 pm). One of the copper surroundings is (pseudo)tetragonally elongated (av. 209/194 pm), the other exhibits an unusual splitting into three long and three short bonds (av. 204/193 pm) in meridional positions. Some structural relations are discussed.

A second-order Jahn-Teller distortion in the solid: the phase transition in VSx

1986 ◽  
Vol 116 (1) ◽  
pp. 113-128 ◽  
Author(s):  
Jérôme Silvestre ◽  
Wolfgang Tremel ◽  
Roald Hoffmann
Keyword(s):  
Phase Transition ◽  
Second Order ◽  
Teller Distortion ◽  
Jahn Teller ◽  
Jahn Teller Distortion
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