Related Experiment Video
Updated: Aug 26, 2026

Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
Magnetic determination of H(c2) under accurate alignment in (TMTSF)2ClO4
1Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Abstract:
Cantilever magnetometry has been used to measure the upper critical magnetic field H(c2) of the quasi-one-dimensional molecular organic superconductor (TMTSF)2ClO4. From simultaneous resistivity and torque magnetization experiments conducted under precise field alignment, H(c2) at low temperature is shown to reach 5 T, nearly twice the Pauli paramagnetic limit imposed on spin singlet superconductors. These results constitute the first thermodynamic evidence for a large H(c2) in this system and provide support for spin triplet pairing in this unconventional superconductor.
Related Concept Videos
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
Chemical Shift: Internal References and Solvent Effects
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...
2D NMR: Overview of Heteronuclear Correlation Techniques
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
2D NMR: Overview of Homonuclear Correlation Techniques
COSY90 is the standard two-dimensional (2D) COSY experiment that...
