0000000000010770

AUTHOR

Andrew Wildes

0000-0003-3957-2818

showing 2 related works from this author

Spin-chain correlations in the frustrated triangular lattice material CuMnO$_2$

2020

The Ising triangular lattice remains the classic test-case for frustrated magnetism. Here we report neutron scattering measurements of short range magnetic order in CuMnO$_2$, which consists of a distorted lattice of Mn$^{3+}$ spins with single-ion anisotropy. Physical property measurements on CuMnO$_2$ are consistent with 1D correlations caused by anisotropic orbital occupation. However the diffuse magnetic neutron scattering seen in powder measurements has previously been fitted by 2D Warren-type correlations. Using neutron spectroscopy, we show that paramagnetic fluctuations persist up to $\sim$25 meV above TN= 65 K. This is comparable to the incident energy of typical diffractometers, a…

PhysicsCondensed matter physicsStrongly Correlated Electrons (cond-mat.str-el)MagnetismFOS: Physical sciences02 engineering and technologyNeutron scattering021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciencesNeutron spectroscopyCondensed Matter - Strongly Correlated ElectronsParamagnetism0103 physical sciencesAntiferromagnetismGeneral Materials ScienceIsing modelHexagonal lattice010306 general physics0210 nano-technologyAnisotropy
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Magnetism of monomer MnO and heterodimer FePt@MnO nanoparticles

2017

We report about the magnetic properties of antiferromagnetic (AF) MnO nanoparticles (NPs) with different sizes (6--19 nm). Using a combination of polarized neutron scattering and magnetometry, we were able to resolve previously observed peculiarities. Magnetometry, on the one hand, reveals a peak in the zero-field-cooled (ZFC) magnetization curves at low temperatures $(\ensuremath{\sim}25$ K) but $no$ feature around the N\'eel temperature at 118 K. On the other hand, polarized neutron scattering shows the expected behavior of the AF order parameter vanishing around 118 K. Moreover, hysteresis curves measured at various temperatures reveal an exchange-bias effect, indicating a coupling of an…

Materials scienceCondensed Matter - Mesoscale and Nanoscale PhysicsCondensed matter physicsMagnetic momentMagnetismFOS: Physical sciences02 engineering and technologyNeutron scattering021001 nanoscience & nanotechnology01 natural sciencesCondensed Matter::Materials ScienceMagnetizationFerromagnetismFerrimagnetismMesoscale and Nanoscale Physics (cond-mat.mes-hall)0103 physical sciencesAntiferromagnetismddc:530Condensed Matter::Strongly Correlated Electrons010306 general physics0210 nano-technologySuperparamagnetismPhysical Review B
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