Elizabeth M. Carnicom

Structure and characterization of charge transfer complexes of benzo[1,2-b:3,4-b′:5,6-b′′]trithiophene [C3h-BTT]

Four charge-transfer complexes of C3h-BTT (2) with the organic acceptors TCNQ, F4TCNQ, chloranil, and fluoranil were prepared and crystallographically characterized. All four complexes form mixed stacks of donors and acceptors in a 1u2006:u20061 or 2u2006:u20061 stoichiometry. The degree of charge transfer in these complexes was estimated based on bond distances, infrared spectroscopy, and magnetic properties. Of the four complexes, C3h-BTT·F4TCNQ exhibited the highest ionicity with ρ = 0.27e. All four complexes were diamagnetic.

TaRh2B2 and NbRh2B2: Superconductors with a chiral noncentrosymmetric crystal structure

Two superconductors with a new chiral noncentrosymmetric crystal structure and Hc2 values above the Pauli limit. It is a fundamental truth in solid compounds that the physical properties follow the symmetry of the crystal structure. Nowhere is the effect of symmetry more pronounced than in the electronic and magnetic properties of materials—even the projection of the bulk crystal symmetry onto different crystal faces is known to have a substantial impact on the surface electronic states. The effect of bulk crystal symmetry on the properties of superconductors is widely appreciated, although its study presents substantial challenges. The effect of a lack of a center of symmetry in a crystal structure, for example, has long been understood to necessitate that the wave function of the collective electron state that gives rise to superconductivity has to be more complex than usual. However, few nonhypothetical materials, if any, have actually been proven to display exotic superconducting properties as a result. We introduce two new superconductors that in addition to having noncentrosymmetric crystal structures also have chiral crystal structures. Because the wave function of electrons in solids is particularly sensitive to the host material’s symmetry, crystal structure chirality is expected to have a substantial effect on their superconducting wave functions. Our two experimentally obtained chiral noncentrosymmetric superconducting materials have transition temperatures to superconductivity that are easily experimentally accessible, and our basic property characterization suggests that their superconducting properties may be unusual. We propose that their study may allow for a more in-depth understanding of how chirality influences the properties of superconductors and devices that incorporate them.

Superconductivity in the Nb-Ru-Ge σ phase

We show that the previously unreported ternary

Superconductivity in the superhard boride WB4.2

sigma

Stabilizing the Tb-based 214 cuprate by partial Pd substitution

-phase material Nb

The LaPdIn 4 indide and elementary properties of the La T In 4 ( T = Ni, Pd, Pt) materials family

_{20.4}

The Chiral Non-Centrosymmetric Superconductors TaRh

Ru

_2

_{5.7}

B

Ge

_2

_{3.9}