Orthorhombic distortion in Au nanoparticles induced by high pressure

CrystEngComm ◽  
2019 ◽  
Vol 21 (22) ◽  
pp. 3451-3459 ◽  
Author(s):  
Rubén Mendoza-Cruz ◽  
Prakash Parajuli ◽  
H. Joazet Ojeda-Galván ◽  
Ángel Gabriel Rodríguez ◽  
Hugo R. Navarro-Contreras ◽  
...  
Keyword(s):  
High Pressure ◽  
Lattice Distortion ◽  
Au Nanoparticles ◽  
Orthorhombic Distortion ◽  
Orthorhombic Lattice

A shape-dependent orthorhombic lattice distortion is induced in Au nanoparticles below 12 GPa in a DAC.

Studies on the Local Structure and the Spin Hamiltonian Parameters for Co2+ in CaTiO3

2008 ◽  
Vol 278 ◽  
pp. 55-62 ◽  
Author(s):  
Guang Duo Lu ◽  
Shao Yi Wu ◽  
Hua Ming Zhang ◽  
Li Hua Wei
Keyword(s):  
Local Structure ◽  
Lattice Distortion ◽  
Impurity Center ◽  
Orthorhombic Symmetry ◽  
Spin Hamiltonian ◽  
Orthorhombic Distortion ◽  
Local Lattice Distortion ◽  
Local Lattice ◽  
Crystal Field Parameters ◽  
Hamiltonian Parameters

The local structure and the spin Hamiltonian parameters g factors gi (i =x, y and z) and the hyperfine structure constants Ai for Co2+ in orthorhombic CaTiO3 are theoretically investigated from diagonalization of 6 × 6 energy matrix within the 4T1 ground state for a 3d7 ion in orthorhombic symmetry. In the calculations, the contributions from the admixtures of various J states (J=1/2, 3/2, 5/2), the ligand orbitals and spin-orbit coupling and the fourth-order orthorhombic field parameter, which were usually neglected in the previous works, are taken into account. The crystal-field parameters are determined from the superposition model in consideration of the suitable lattice distortion due to the charge and size mismatching substitution of Ti4+ by Co2+. Based on the studies, the bond lengths R1 and R2 in the xy plane are estimated to suffer the relative alternation R ≈ 5.4%, yielding more significant orthorhombic distortion in the impurity center as compared with that for the host Ti4+ site in pure crystal. The calculation results based on the above local lattice distortion show reasonable agreement with the observed values. The various contributions to the spin Hamiltonian parameters are discussed. Present studies may theoretically verify that the impurity Co2+ occupies the 6-fold coordinated Ti4+ site rather than the 12-fold coordinated Ca2+ site, associated with the enhanced orthorhombic distortion due to the mismatching substitution.

scholarly journals Anomalous Suppression of the Orthorhombic Lattice Distortion in SuperconductingBa(Fe1−xCox)2As2Single Crystals

2010 ◽  
Vol 104 (5) ◽  
Author(s):  
S. Nandi ◽  
M. G. Kim ◽  
A. Kreyssig ◽  
R. M. Fernandes ◽  
D. K. Pratt ◽  
...  
Keyword(s):  
Lattice Distortion ◽  
Orthorhombic Lattice

Orthorhombic Lattice Distortion of YBa2Cu3O7−y and the Superconducting Transition Temperature

1988 ◽  
Vol 149 (2) ◽  
pp. K145-K148
Author(s):  
E. M. Gololobov ◽  
A. S. Gurevich ◽  
E. L. Mager ◽  
Z. V. Mezhevich ◽  
N. A. Prytkova ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Lattice Distortion ◽  
Superconducting Transition ◽  
Orthorhombic Lattice

Structures des phases paraélectrique et ferroélectrique de Pb2KNb5O15

1999 ◽  
Vol 55 (4) ◽  
pp. 459-466 ◽  
Author(s):  
Philippe Sciau ◽  
Gilbert Calvarin ◽  
Jean Ravez
Keyword(s):  
Lattice Distortion ◽  
Paraelectric Phase ◽  
Rietveld Method ◽  
Lattice Parameters ◽  
Powder Diffraction Data ◽  
Orthorhombic Distortion ◽  
Special Position ◽  
Space Group ◽  
X Ray ◽  
Local Polarization

The paraelectric and the ferroelectric/ferroelastic structures of Pb2KNb5O15 have been refined by the Rietveld method from neutron and X-ray powder diffraction data. The paraelectric phase is tetragonal (space group P4/mbm) with lattice parameters a t = 12.646 (1) and c t = 3.9551 (2) Å at 790 K. The Pb- and K-atom distribution has been determined. It was established that the Pb atoms situated on the 15-coordinate sites are not on the special position (2mm) but are distributed over two disordered positions as in the tetragonal phase of Pb2KTa5O15. The ferroelectric/ferroelastic phase is orthorhombic. The space group of the average structure is Cm2m and the lattice parameters are a o = 17.779 (2), b o = 18.015 (2), c o = 3.9209 (4) Å at 294 K and a o = 17.756 (1), b o = 18.019 (1), c o = 3.9141 (2) Å at 81 K. It is isostructural with the average ferroelectric/ferroelastic structure of PbNb2O6. The orthorhombic distortion is of the same order but the Curie temperature is lowered by the substitution 2K+–Pb2+. The structures of PbNb2O6, PbTa2O6, Pb2KNb5O15 and Pb2KTa5O15 are compared. The ferroelectric polarization of the niobates is due to both the Pb off-site position and the Nb displacements, which induce a distortion of the oxygen lattice. In PbTa2O6, the oxygen-lattice distortion is very weak. The polarization seems to be due only to the Pb atom. In the tantalates the substitution 2K+–Pb2+ should weaken the correlations between the Pb atoms and consequently suppress the ferroelectric transition. Only a local polarization should take place; this might be the origin of the dielectric relaxation observed in this compound.

Lattice distortion of NiO under high pressure

1996 ◽  
Vol 54 (14) ◽  
pp. R9581-R9584 ◽  
Author(s):  
Taizo Sasaki
Keyword(s):  
High Pressure ◽  
Lattice Distortion

scholarly journals Lattice distortion and stability of (Co0.2Cu0.2Mg0.2Ni0.2Zn0.2)O high-entropy oxide under high pressure

2020 ◽  
Vol 8 ◽  
pp. 100102
Author(s):  
B. Cheng ◽  
H. Lou ◽  
A. Sarkar ◽  
Z. Zeng ◽  
F. Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
Lattice Distortion ◽  
High Entropy

scholarly journals Phonon triggered rhombohedral lattice distortion in vanadium at high pressure

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Daniele Antonangeli ◽  
Daniel L. Farber ◽  
Alexei Bosak ◽  
Chantel M. Aracne ◽  
David G. Ruddle ◽  
...  
Keyword(s):  
High Pressure ◽  
Lattice Distortion
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