313 research outputs found
Commensurate to incommensurate magnetic phase transition in Honeycomb-lattice pyrovanadate Mn2V2O7
We have synthesized single crystalline sample of MnVO using
floating zone technique and investigated the ground state using magnetic
susceptibility, heat capacity and neutron diffraction. Our magnetic
susceptibility and heat capacity reveal two successive magnetic transitions at
19 K and 11.8 K indicating two distinct magnetically
ordered phases. The single crystal neutron diffraction study shows that in the
temperature () range 11.8 K 19 K the magnetic structure is
commensurate with propagation vector , while upon lowering
temperature below 11.8 K an incommensurate magnetic order emerges
with and the magnetic structure can be represented by
cycloidal modulation of the Mn spin in plane. We are reporting this
commensurate to incommensurate transition for the first time. We discuss the
role of the magnetic exchange interactions and spin-orbital coupling on the
stability of the observed magnetic phase transitions.Comment: 8 pages, 7 figure
Electron Capture Rates in Collisions of H+ Ions with Si Atoms: Capture by the Ground and Excited State
Recommended from our members
Magnetoelastic coupling and ferromagnetic-type in-gap spin excitations in multiferroic α-Cu2V2O7
We investigate magnetoelectric coupling and low-energy magnetic excitations in multiferroic α-Cu2V2O7 by detailed thermal expansion, magnetostriction, specific heat and magnetization measurements in magnetic fields up to 15 T and by high-field/high-frequency electron spin resonance studies. Our data show negative thermal expansion in the temperature range ≤200 K under study. Well-developed anomalies associated with the onset of multiferroic order (canted antiferromagnetism with a significant magnetic moment and ferroelectricity) imply pronounced coupling to the structure. We detect anomalous entropy changes in the temperature regime up to ∼80 K which significantly exceed the spin entropy. Failure of Grüneisen scaling further confirms that several dominant ordering phenomena are concomitantly driving the multiferroic order. By applying external magnetic fields, anomalies in the thermal expansion and in the magnetization are separated. Noteworthy, the data clearly imply the development of a canted magnetic moment at temperatures above the structural anomaly. Low-field magnetostriction supports the scenario of exchange-striction driven multiferroicity. We observe low-energy magnetic excitations well below the antiferromagnetic gap, i.e., a ferromagnetic-type resonance branch associated with the canted magnetic moment arising from Dzyaloshinsii-Moriya (DM) interactions. The anisotropy parameter meV indicates a sizeable ratio of DM- and isotropic magnetic exchange
Doping site induced alteration of incommensurate antiferromagnetic ordering in Fe-doped MnNiGe alloys
Role of crystal field ground state in the classical spin-liquid behavior of a quasi-one dimensional spin-chain system Sr3NiPtO6
The spin-chain compound Sr3NiPtO6 is known to have a nonmagnetic ground
state. We have investigated the nature of ground state of Sr3NiPtO6 using
magnetic susceptibility , heat capacity , muon spin
relaxation (SR) and inelastic neutron scattering (INS) measurements. The
and do not exhibit any pronounced anomaly that can be
associated with a phase transition to a magnetically ordered state. Our SR
data confirm the absence of long-range magnetic ordering down to 0.04 K.
Furthermore, the muon spin relaxation rate increases below 20 K and exhibits
temperature independent behavior at low temperature, very similar to that
observed in a quantum spin-liquid system. The INS data show a large excitation
near 8~meV, and the analysis of the INS data reveals a singlet CEF ground state
with a first excited CEF doublet state at = 7.7 meV. The
estimated CEF parameters reveal a strong planar anisotropy in the calculated
, consistent with the reported behavior of the of single
crystal Sr3NiPtO6. We propose that the nonmagnetic singlet ground state and a
large (much larger than the exchange interaction
) are responsible for the absence of long-range magnetic
ordering and can mimic a classical spin-liquid behavior in this quasi-1D spin
chain system Sr3NiPtO6. The classical spin-liquid ground state observed in
Sr3NiPtO6 is due to the single-ion property, which is different from the
quantum spin-liquid ground state observed in geometrically frustrated systems,
where two-ion exchanges play an important role.Comment: 11 pages, 10 figures, 1 tabl
Nodeless time-reversal symmetry breaking in the centrosymmetric superconductor Sc5Co4Si10 probed by muon-spin spectroscopy
- …