skip to main content

Search for: All records

Creators/Authors contains: "Aronson, M. C."

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Sc 3 Mn 3 Al 7 Si 5 is a rare example of a correlated metal in which the Mn moments form a kagome lattice. The absence of magnetic ordering to the lowest temperatures suggests that geometrical frustration of magnetic interactions may lead to strong magnetic fluctuations. We have performed inelastic neutron scattering measurements on Sc 3 Mn 3 Al 7 Si 5 , finding that phonon scattering dominates for energies from ∼20–50 meV. These results are in good agreement with ab initio calculations of the phonon dispersions and densities of states, and as well reproduce the measured specific heat.more »A weak magnetic signal was detected at energies less than ∼10 meV, present only at the lowest temperatures. The magnetic signal is broad and quasielastic, as expected for metallic paramagnets.« less
    Free, publicly-accessible full text available October 12, 2022
  2. Sc 3 Mn 3 Al 7 Si 5 is a rare example of a correlated metal in which the Mn moments form a kagome lattice. The absence of magnetic ordering to the lowest temperatures suggests that geometrical frustration of magnetic interactions may lead to strong magnetic fluctuations. We have performed inelastic neutron scattering measurements on Sc 3 Mn 3 Al 7 Si 5 , finding that phonon scattering dominates for energies from ∼20–50 meV. These results are in good agreement with ab initio calculations of the phonon dispersions and densities of states, and as well reproduce the measured specific heat.more »A weak magnetic signal was detected at energies less than ∼10 meV, present only at the lowest temperatures. The magnetic signal is broad and quasielastic, as expected for metallic paramagnets« less
    Free, publicly-accessible full text available October 12, 2022
  3. We report here the properties of single crystals of La 2 Ni 2 In . Electrical resistivity and specific heat measurements concur with the results of density functional theory calculations, finding that La 2 Ni 2 In is a weakly correlated metal, where the Ni magnetism is almost completely quenched, leaving only a weak Stoner enhancement of the density of states. Superconductivity is observed at temperatures below 0.9 K. A detailed analysis of the field and temperature dependencies of the resistivity, magnetic susceptibility, and specific heat at the lowest temperatures reveals that La 2 Ni 2 In is a dirtymore »type-II superconductor with likely s -wave gap symmetry. Nanoclusters of ferromagnetic inclusions significantly affect the subgap states resulting in a nonexponential temperature dependence of the specific heat C ( T ) at T ≪ T c .« less
  4. The 3d transition metal insulator Bi2CrAl3O9 forms with a quasi-one-dimensional structure characterized by linear chains of edge-sharing, Cr-and Al-centered, distorted octahedra. The UV/Vis spectrum of high-quality single crystals is marked by broad absorption edges corresponding to direct transitions across a 1.36-eV insulating gap. Measurements of dc magnetic susceptibility χ reveal a fluctuating moment of 2.60±0.01μB/Cr—reduced from the 3.87μB/Cr expected for Cr3+, while the Weiss temperature ΘW=−21±1 K implies that the prevailing local moment interactions are weakly antiferromagnetic in nature. Some 10% of the fluctuating moment is quenched, presumably due to the onset of an antiferromagnetic or spin glass phase atmore »temperature T★=98±3 K, while measurements of magnetization versus field H at T≤10 K scale as H/T0.68(4), suggesting the presence of quantum fluctuations associated with a disordered phase. Density functional theory calculations carried out within the generalized gradient approximation are in excellent agreement with experimental results, asserting that short-range magnetic interactions remnant above T★ stabilize the insulating state« less