32 research outputs found
Specific heat of CaNaFeAs single crystals: unconventional s multi-band superconductivity with intermediate repulsive interband coupling and sizable attractive intraband couplings
We report a low-temperature specific heat study of high-quality single
crystals of the heavily hole doped superconductor
CaNaFeAs. This compound exhibits bulk
superconductivity with a transition temperature \,K, which is
evident from the magnetization, transport, and specific heat measurements. The
zero field data manifests a significant electronic specific heat in the normal
state with a Sommerfeld coefficient mJ/mol K. Using a
multi-band Eliashberg analysis, we demonstrate that the dependence of the zero
field specific heat in the superconducting state is well described by a
three-band model with an unconventional s pairing symmetry and gap
magnitudes of approximately 2.35, 7.48, and -7.50 meV. Our analysis
indicates a non-negligible attractive intraband coupling,which contributes
significantly to the relatively high value of . The Fermi surface averaged
repulsive and attractive coupling strengths are of comparable size and outside
the strong coupling limit frequently adopted for describing high- iron
pnictide superconductors. We further infer a total mass renormalization of the
order of five, including the effects of correlations and electron-boson
interactions.Comment: 8 Figures, Submitted to PR
The Mediterranean problems in the context of the international aspects of the civil war in Spain 1936-1939
In their study, the researchers has made an attempt to analyze such international aspects of the Spanish Civil War as the Mediterranean aspect. The researchers looks at it in the context of international relations on the base of the materials from the Archives of Foreign policy of the Russian Ministry of Foreign Affairs, published diplomacy documents of main European countrie
Magnetic Anisotropy of Cr(III) Ions in Polymeric Oxalate Complexes as Revealed by HF-ESR Spectroscopy
3D oxalate-based coordination polymers: Relationship between structure, magnetism and color, studied by high-field ESR spectroscopy
The Mediterranean problems in the context of the international aspects of the civil war in Spain 1936-1939
In their study, the researchers has made an attempt to analyze such international aspects of the Spanish Civil War as the Mediterranean aspect. The researchers looks at it in the context of international relations on the base of the materials from the Archives of Foreign policy of the Russian Ministry of Foreign Affairs, published diplomacy documents of main European countrie
Slow magnetic relaxations in manganese(III) tetra(meta-fluorophenyl)porphyrin-tetracyanoethenide : comparison with the relative single chain magnet ortho compound
Mn(III) tetra(meta-fluorophenyl)porphyrin-tetracyanoethenide coordination polymer (abbreviated meta-F) was synthesized and crystallographically and magnetically characterized. The compound crystallizes in the space group C2/c with four equivalent molecules in the unit cell arranged along two symmetry related nonparallel linear chain directions. Magnetic properties were studied by SQUID dc magnetization and ac susceptibility techniques and high field-high frequency electron spin resonance (HF-ESR). Glassy transition to a ferromagnetic-like state is observed at 10 K accompanied by slow magnetic relaxations. The glassiness is interpreted as due to 3D domain wall pinning. In a bias dc magnetic field the width of the relaxation time distribution decreases and the relaxations become similar to the relaxations of the single chain magnet Mn(III) tetra(ortho-fluorophenyl)porphyrin-tetracyanoethenide (abbreviated ortho-F), for which comparative HF-ESR studies were also conducted in this work. Magnetic properties of these two compounds are compared, and the nature of magnetic relaxations in meta-F is discussed
Reversible Water-Induced Structural and Magnetic Transformations and Selective Water Adsorption Properties of Poly(manganese 1,1′-ferrocenediyl-bis(H-phosphinate))
© 2016 American Chemical Society.A flexible and hydrolytically stable metal-organic framework [Mn(H2O)2(Fc(PHOO)2)·2H2O]n has been synthesized using ferrocene-based ligand bearing phosphinic groups (Fc(PHOOH)2 = 1,1′-ferrocenediyl-bis(H-phosphinic acid)). In this compound manganese atoms are bound by phosphinate fragments to give infinite chains, and the latter are interconnected by ferrocene groups to form two-dimensional coordination polymer. The elimination of both coordinated and lattice water molecules during heating up to 150 °C produced the compound, which is nonporous for nitrogen, but can selectively adsorb water over methanol and other solvents at 298 K. The reversible structural transformation during adsorption/desorption of water is also reflected in a change of magnetic properties of the metal-organic framework
Reversible Water-Induced Structural and Magnetic Transformations and Selective Water Adsorption Properties of Poly(manganese 1,1′-ferrocenediyl-bis(H-phosphinate))
© 2016 American Chemical Society.A flexible and hydrolytically stable metal-organic framework [Mn(H2O)2(Fc(PHOO)2)·2H2O]n has been synthesized using ferrocene-based ligand bearing phosphinic groups (Fc(PHOOH)2 = 1,1′-ferrocenediyl-bis(H-phosphinic acid)). In this compound manganese atoms are bound by phosphinate fragments to give infinite chains, and the latter are interconnected by ferrocene groups to form two-dimensional coordination polymer. The elimination of both coordinated and lattice water molecules during heating up to 150 °C produced the compound, which is nonporous for nitrogen, but can selectively adsorb water over methanol and other solvents at 298 K. The reversible structural transformation during adsorption/desorption of water is also reflected in a change of magnetic properties of the metal-organic framework
Reversible Water-Induced Structural and Magnetic Transformations and Selective Water Adsorption Properties of Poly(manganese 1,1′-ferrocenediyl-bis(H-phosphinate))
© 2016 American Chemical Society.A flexible and hydrolytically stable metal-organic framework [Mn(H2O)2(Fc(PHOO)2)·2H2O]n has been synthesized using ferrocene-based ligand bearing phosphinic groups (Fc(PHOOH)2 = 1,1′-ferrocenediyl-bis(H-phosphinic acid)). In this compound manganese atoms are bound by phosphinate fragments to give infinite chains, and the latter are interconnected by ferrocene groups to form two-dimensional coordination polymer. The elimination of both coordinated and lattice water molecules during heating up to 150 °C produced the compound, which is nonporous for nitrogen, but can selectively adsorb water over methanol and other solvents at 298 K. The reversible structural transformation during adsorption/desorption of water is also reflected in a change of magnetic properties of the metal-organic framework