Publications (24)
Electrodynamics of BaFe2As2 from infrared measurements under pressure
L. Baldassarre, A. Perucchi, P. Postorino +8
We report on an infrared study on the undoped compound BaFe2As2 as a function of both pressure (up to about 10 GPa) at three temperatures (300, 160, and 110 K). The evolution with…
Small and large polarons in nickelates, manganites, and cuprates
P. Calvani, P. Dore, S. Lupi +6
By comparing the optical conductivities of La_{1.67}Sr_{0.33}NiO_{4} (LSNO), Sr_{1.5}La_{0.5}MnO_4 (SLMO), Nd_2CuO_{4-y} (NCO), and Nd_{1.96}Ce_{0.04}CuO_{4} (NCCO), we have identi…
Effect of Al doping on the optical phonon spectrum in Mg(1-x)Al(x)B(2)
P. Postorino, A. Congeduti, P. Dore +5
Raman and infrared absorption spectra of Mg(1-x)Al(x)B(2) have been collected for 0<x<0.5 in the spectral range of optical phonons. The x-dependence of the peak frequency, the widt…
Clean and Dirty Superconductivity in Pure, Al doped, and Neutron Irradiated MgB2: a Far-Infrared Study
M. Ortolani, D. Di Castro, P. Postorino +4
The effects of Al substitution and neutron irradiation on the conduction regime (clean or dirty) of the - and -band of MgB have been investigated by means of far-infr…
Vibrational spectrum of solid picene (C_22H_14)
B. Joseph, L. Boeri, L. Malavasi +11
Recently, Mitsuhashi et al., have observed superconductivity with transition temperature up to 18 K in potassium doped picene (C22H14), a polycyclic aromatic hydrocarbon compound […
Raman spectroscopy study of the interface structure in (CaCuO2)n/(SrTiO3)m superlattices
D. Di Castro, S. Caramazza, D. Innocenti +4
Raman spectra of CaCuO2/SrTiO3 superlattices show clear spectroscopic marker of two structures formed in CaCuO2 at the interface with SrTiO3. For non-superconducting superlattices,…
Interplay of the electronic and lattice degrees of freedom in A_{1-x}Fe_{2-y}Se_{2} superconductors under pressure
M. Bendele, C. Marini, B. Joseph +12
The local structure and electronic properties of RbFeSe are investigated by means of site selective polarized x-ray absorption spectroscopy at the iron and sele…
Electrodynamics of superconducting pnictide superlattices
A. Perucchi, F. Capitani, P. Di Pietro +8
It has been recently reported (S. Lee et al., Nature Materials 12, 392, 2013) that superlattices where layers of the 8% Co-doped BaFe2As2 superconducting pnictide are intercalated…
Infrared absorption from Charge Density Waves in magnetic manganites
P. Calvani, G. De Marzi, P. Dore +5
The infrared absorption of charge density waves coupled to a magnetic background is first observed in two manganites La{1-x}Ca{x}MnO{3} with x = 0.5 and x = 0.67. In both cases a B…
Infrared response of ordered polarons in layered perovskites
P. Calvani, A. Paolone, P. Dore +4
We report on the infrared absorption spectra of three oxides where charged superlattices have been recently observed in diffraction experiments. In LaSrNiO, p…
Multi-gap superconductivity in a BaFe1.84Co0.16As2 film from optical measurements at terahertz frequencies
A. Perucchi, L. Baldassarre, C. Marini +10
We measured the THz reflectance properties of a high quality epitaxial thin film of the Fe-based superconductor BaFeCoAs with T=22.5 K. The film was grown…
Fano effect in the plane of NdCeCuO: evidence of phonon interaction with a polaronic background
S. Lupi, M. Capizzi, P. Calvani +4
Reflectance measurements in properly selected samples of NdCeCuO with different carrier concentrations provide a firm evidence of Fano antiresonances for…
A combined experimental and computational study of the pressure dependence of the vibrational spectrum of solid picene C_22H_14
F. Capitani, M. Hoeppner, B. Joseph +9
We present high-quality optical data and density functional perturbation theory calculations for the vibrational spectrum of solid picene (CH) under pressure up to 8…
Coexistence of pressure-induced structural phases in bulk black phosphorus: a combined x-ray diffraction and Raman study up to 18 GPa
B. Joseph, S. Caramazza, F. Capitani +7
We report a study of the structural phase transitions induced by pressure in bulk black phosphorus by using both synchrotron x-ray diffraction for pressures up to 12.2 GPa and Rama…
Far infrared properties of the rare-earth scandate DyScO3
L. Baldassarre, A. Perucchi, S. Lupi +1
We present reflectance measurements in the infrared region on a single crystal the rare earth scandate DyScO3. Measurements performed between room temperature and 10 K allow to det…
Polarization analysis of first- and second-order Raman scattering from MoTe single crystal
S. Caramazza, A. Collina, E. Stellino +2
We report on Raman experiments performed on a single crystal MoTe sample. The system belongs to the wide family of Transition Metal Dichalcogenides which includes several of th…
Two-band conductivity of a FeSeTe film by reflectance measurements in the terahertz and infrared range
A. Perucchi, B. Joseph, S. Caramazza +7
We report an infrared spectroscopy study of a 200 nm thick FeSeTe film grown on LaAlO with T=13.7 K. We analyze the 20 K normal state absolute reflectance R…
Multi-band conductivity and multi-gap superconductivity in V3Si from optical measurements on films at terahertz frequencies
A. Perucchi, D. Nicoletti, M. Ortolani +13
The possibility of multi-band conductivity and multi-gap superconductivity is explored in oriented V3Si thin films by means of reflectance and transmittance measurements at teraher…
Two-band parallel conductivity at terahertz frequencies in the superconducting state of MgB.
M. Ortolani, P. Dore, D. Di Castro +7
The optical response of the two-band superconductor MgB has been studied in the 0.7-4 THz range on films with very low impurity level. The effect of the high-energy -gap is…
Optical conductivity of CuO_2 infinite-layer films
P. Dore, P. Calvani, G. De Marzi +5
The infrared conductivity of CaCuO_2, SrCuO_{2-y}, and Sr_{0.85}Nd_{0.15}CuO_2 infinite-layer films is obtained from reflectivity measurements by taking into account the substrate…
Pressure and alloying effects on the metal to insulator transition in NiS{2-x}Se{x} studied by infrared spectroscopy
A. Perucchi, C. Marini, M. Valentini +11
The metal to insulator transition in the charge transfer NiS{2-x}Se{x} compound has been investigated through infrared reflectivity. Measurements performed by applying pressure to…
Pressure-tuning of the electron-phonon coupling: the insulator to metal transition in manganites
P. Postorino, A. Congeduti, P. Dore +5
A comprehensive understanding of the physical origin of the unique magnetic and transport properties of A_(1-x)A'^xMnO_3 manganites (A = trivalent rare-earth and A' = divalent alka…
The optical phonon spectrum of SmFeAsO
C. Marini, C. Mirri, G. Profeta +12
We measured the Raman and the Infrared phonon spectrum of SmFeAsO polycrystalline samples. We also performed Density Functional Theory calculations within the pseudopotential appro…
Emergent Dirac carriers across a pressure-induced Lifshitz transition in black phosphorus
P. Di Pietro, M. Mitrano, S. Caramazza +11
The phase diagrams of correlated systems like cuprates or pnictides high-temperature superconductors are characterized by a topological change of the Fermi surface under continuous…