Related Experiment Video
Updated: Aug 14, 2026
08:53
Angle-resolved Photoemission Spectroscopy At Ultra-low Temperatures
Published on: October 9, 2012
In-plane anisotropy of upper critical field in Sr2RuO4
1Department of Physics, Kyoto University, Kyoto 606-8502, Japan and Core Research for Evolutional Science and Technology of Japan Science and Technology Corporation (CREST-JST), Kawaguchi, Saitama 332-0012, Japan.
Physical Review Letters
|October 4, 2000
Summary
Researchers studied strontium ruthenate (Sr2RuO4) superconductors in magnetic fields. They observed a fourfold anisotropy in the upper critical field and a secondary superconducting phase, suggesting a line-node gap.
Area of Science:
- Condensed matter physics
- Superconductivity research
- Materials science
Background:
- Sr2RuO4 is a candidate for spin-triplet superconductivity.
- Understanding its superconducting phases under magnetic fields is crucial.
Purpose of the Study:
- Investigate the superconducting behavior of Sr2RuO4.
- Characterize the anisotropy of its upper critical field.
- Identify potential new superconducting phases.
Main Methods:
- Magnetic field experiments on Sr2RuO4.
- Measurements of ac susceptibility.
- Specific heat measurements.
Main Results:
- Observed a 3% fourfold anisotropy in the upper critical field (H(c2)).
- Detected a secondary superconducting transition below H(c2).
- Anisotropy and secondary transition vanished above 0.8 K or with field misalignment.
Conclusions:
- Results are consistent with a predicted second superconducting phase.
- This phase likely possesses a line-node gap.
- Further research needed to confirm the nature of the observed phenomena.
Related Concept Videos
02:42Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
02:58Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
01:18Mohr's Circle for Plane Strain
Mohr's circle is a crucial graphical method used to analyze plane strain by plotting strain on a set of cartesian coordinates, where the abscissa is normal strain ∈ and the ordinate is shear strain γ. Similarly to Mohr’s circle for plane stress, two points X and Y are plotted. Their coordinates are (∈x, -γXY) and (∈Y, γXY), respectively.
Mohr's circle visually represents the strain states under various conditions, which is essential for understanding material behavior. The center of Mohr's...
Mohr's circle visually represents the strain states under various conditions, which is essential for understanding material behavior. The center of Mohr's...
01:29Three-Dimensional Analysis of Strain
Three-dimensional strain analysis is crucial for understanding how materials deform under stress, particularly in elastic, homogeneous materials. This method employs principal stress axes to simplify complex stress states into more understandable forms. Subjected to stress, a small cubic element within a material either expands or contracts along these axes, transforming into a rectangular parallelepiped. This transformation effectively illustrates the material's deformation. The principal...
01:26Imperfections in Crystal Structure: Stoichiometric Point Defects
Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...