216 research outputs found
Magnetic ordering in the = 0 Nickelate NiRhO prepared via a solid-state metathesis
In spinel-type nickelate NiRhO, magnetic ordering is observed upon
the sample synthesized via kinetically controlled low-temperature solid-state
metathesis, as opposed to previously-reported samples obtained through
conventional solid-state reaction. Our findings are based on a combination of
bulk susceptibility and specific heat measurements that disclose a Nel
transition temperature of = 45 K in this material, which might feature
spin-orbit entanglement in the tetragonally-coordinated Mott insulators.
The emergence of magnetic ordering upon alteration of the synthesis route
indicates that the suppression of magnetic ordering in the previous sample was
rooted in the cation-mixing assisted by the entropy gain that results from
high-temperature reactions. Furthermore, the = 0 physics, instead
of solely the spin-only , describes the observed enhancement of
effective magnetic moment well. Overseeing all observations and speculations,
we propose that the possible mechanism responsible for the emergent magnetic
orderings in NiRhO is the condensation of = 0 exciton,
driven by the interplay of the tetragonal crystal field and superexchange
interactions.Comment: 7 pages, 5 figures, accepted in Physical Review Material
Superconductivity at 12 K in LaIOs: a 5d metal with osmium honeycomb layer
We discovered superconductivity at = 12 K in a layered compound
LaIOs with osmium honeycomb network. Despite heavy constituent elements
unfavorable for phonon mediated mechanism, is the highest among
lanthanoid iodides made of lighter elements such as LaIRu with =
4.8 K. Electronic anomalies are observed below 60 K similar to those observed
in LaIRu below 140 K. LaIOs is a layered 5d electron system
providing a platform to investigate the interplay between the electronic
anomaly, superconductivity, and strong magnetic field.Comment: 7 pages, 4 figure
Linear Trimer Formation by Three-Center-Four-Electron Bonding in RuP
In molecules like hydrogen, most chemical bonds are formed by sharing two
electrons from each atom in the bonding molecular orbital
(two-center-two-electron (2c2e) bonding). There are, however, different kinds
of chemical bonding. The I3- molecule, for example, is noteworthy because three
iodine atoms are linearly united by sharing four electrons
(three-center-four-electron (3c4e) bonding). Some inorganic solids undergo
phase transitions that result in the formation of "molecules" in their
crystalline frameworks, which are often accompanied by dramatic changes in
physical properties; the metal-to-insulator transition (MIT) in vanadium
dioxide, for example, occurs with the formation of dimer molecules with 2c2e
bonding. We repot the creation of a linear ruthenium trimer with 3c4e bonding
in ruthenium monopnictide at its MIT. Charge transfer from polymerized
phosphorous to ruthenium produces this unusual molecule, with all conduction
electrons trapped by the bonding molecular orbital. Our results demonstrate
that molecules are crucial even in solid crystals as they impact their
electronic properties.Comment: 12 pages, 9 figures, 3 Table
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