Search results for "MAGNETIC PROPERTIES"
showing 10 items of 105 documents
Long-distance spin-transport across the Morin phase transition up to room temperature in ultra-low damping single crystals of the antiferromagnet α-F…
2020
Antiferromagnetic materials can host spin-waves with polarizations ranging from circular to linear depending on their magnetic anisotropies. Until now, only easy-axis anisotropy antiferromagnets with circularly polarized spin-waves were reported to carry spin-information over long distances of micrometers. In this article, we report long-distance spin-transport in the easy-plane canted antiferromagnetic phase of hematite and at room temperature, where the linearly polarized magnons are not intuitively expected to carry spin. We demonstrate that the spin-transport signal decreases continuously through the easy-axis to easy-plane Morin transition, and persists in the easy-plane phase through …
Giant barocaloric effects over a wide temperature range in superionic conductor AgI
2017
Current interest in barocaloric effects has been stimulated by the discovery that these pressure-driven thermal changes can be giant near ferroic phase transitions in materials that display magnetic or electrical order. Here we demonstrate giant inverse barocaloric effects in the solid electrolyte AgI, near its superionic phase transition at ~420 K. Over a wide range of temperatures, hydrostatic pressure changes of 2.5 kbar yield large and reversible barocaloric effects, resulting in large values of refrigerant capacity. Moreover, the peak values of isothermal entropy change (60 J K−1 kg−1 or 0.34 J K−1 cm−3) and adiabatic temperature changes (18 K), which we identify for a starting tempera…
Guest Modulation of Spin-Crossover Transition Temperature in a Porous Iron(II) Metal Organic Framework: Experimental and Periodic DFT Studies
2014
The synthesis, structure, and magnetic properties of three clathrate derivatives of the spin-crossover porous coordination polymer {Fe(pyrazine)[Pt(CN)(4)]} (1) with five-membered aromatic molecules furan, pyrrole, and thiophene is reported. The three derivatives have a cooperative spin-crossover transition with hysteresis loops 14-29 K wide and average critical temperatures T-c=201 K (1.fur), 167 K (1.pyr), and 114.6 K (1.thio) well below that of the parent compound 1 (T-c=295 K), confirming stabilization of the HS state. The transition is complete and takes place in two steps for 1.fur, while 1.pyr and 1.thio show 50% spin transition. For 1.fur the transformation between the HS and IS (mi…
Limiting neutrino magnetic moments with Borexino Phase-II solar neutrino data
2017
A search for the solar neutrino effective magnetic moment has been performed using data from 1291.5 days exposure during the second phase of the Borexino experiment. No significant deviations from the expected shape of the electron recoil spectrum from solar neutrinos have been found, and a new upper limit on the effective neutrino magnetic moment of $\mu_{\nu}^{eff}$ $<$ 2.8$\cdot$10$^{-11}$ $\mu_{B}$ at 90\% c.l. has been set using constraints on the sum of the solar neutrino fluxes implied by the radiochemical gallium experiments.Using the limit for the effective neutrino moment, new limits for the magnetic moments of the neutrino flavor states, and for the elements of the neutrino magne…
Assessment of the CTOCD-DZ methodin a hierarchy of coupled cluster methods
2010
Gauge origin independent calculations of nuclear magnetic shielding tensors are carried out inside the formalism of the continuous transformation of the origin of the current density leading to formal annihilation of its diamagnetic contribution (CTOCD-DZ). We employ the unrelaxed linear response approach with a hierarchy of different coupled cluster methods in order to assess the importance of the level of approximation in the coupled cluster expansion. The basis set dependence of the computed nuclear magnetic shielding constants is also analyzed in the series of correlation consistent basis sets, with the aim of designing optimized basis sets of relatively small size.
Pulsed-field studies of the magnetization reversal in molecular nanomagnets
2004
We report experimental studies of crystals of Mn12 molecular magnetic clusters in pulsed magnetic fields with sweep rates up to 4x10^3 T/s. The steps in the magnetization curve are observed at fields that are shifted with respect to the resonant field values. The shift systematically increases as the rate of the field sweep goes up. These data are consistent with the theory of the collective dipolar relaxation in molecular magnets.
Probing neutrino magnetic moments at the Spallation Neutron Source facility
2015
24 pages.- 8 figures
A Heterobimetallic Anionic 3,6-Connected 2D Coordination Polymer Based on Nitranilate as Ligand
2016
In order to synthesize new coordination polymers with original architectures and interesting magnetic properties, we used the nitranilate ligand (C₆O₄(NO₂)₂2- = C₆N₂O₈2-), derived from the dianionic ligand dhbq2- (2,5-dihydroxy-1,4-benzoquinone = H₂C₆O₄2-). The use of this bis-bidentate bridging ligand led to [(DAMS)₂{FeNa(C₆N₂O₈)₃}·CH₃CN]n (1) (DAMS⁺ = C16H17N₂⁺ = 4-[4-(dimethylamino)-α-styryl]-1-methylpyridinium), a 2D heterometallic coordination polymer presenting an unprecedented structure for any anilato-based compound. This structural type is a 3,6-connected 2D coordination polymer derived from the well-known honeycomb hexagonal structure, where Fe(III) ions alternate with Na⁺ dimers …
Electromagnetic structure of few-nucleon ground states
2015
Experimental form factors of the hydrogen and helium isotopes, extracted from an up-to-date global analysis of cross sections and polarization observables measured in elastic electron scattering from these systems, are compared to predictions obtained in three different theoretical approaches: the first is based on realistic interactions and currents, including relativistic corrections (labeled as the conventional approach); the second relies on a chiral effective field theory description of the strong and electromagnetic interactions in nuclei (labeled $\chi$EFT); the third utilizes a fully relativistic treatment of nuclear dynamics as implemented in the covariant spectator theory (labeled…
Switching nuclearity and Co(II) content through stoichiometry adjustment: {Co(II)6Co(III)3} and {Co(II)Co4(III)} mixed valent complexes and a study o…
2015
We are reporting two new mixed valent Co(ii)/Co(iii) polynuclear complexes, {Co II 6 Co III 3 } and {Co II Co III 4 }, bearing different amount of Co(ii) ions in their cores, through the employment of the multidentate triethanolamine (teaH 3 ) ligand in different stoichiometric ratios. We present a complete picture of the magnetic behaviour of both complexes through a combined usage of the susceptibility, magnetization and X-band EPR data as well as broken-symmetry DFT calculations. Compound 1 shows an atypical spin-only behaviour, probably due to the presence of four and five coordinated Co(ii) sites as well as highly distorted six coordinated Co(ii) ions, promoting a high degree of orbita…