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In this paper we describe high school attitudes toward physics using Semiotic Dynamic Cultural Psychology Theory (SDCPT). A View of Physics questionnaire was used to collect data about the views on physics and physicists with 337 high school (16-18 years old) students. Data were analysed through Multiple Correspondence Analysis and Cluster Analysis. We identified four basic generalized meanings of physics. In particular, it turned out that students see physics as either: A) interesting and important for a technology-based society; b) quite interesting, but badly taught at school and not completely useful for society; c) difficult and irrelevant for society; d) fascinating and important to study at school, but with an underrated value for society. Our study supports the use of the SDCPT framework to refine interpretative models of students' motivation towards physics and develop new ways of teaching physics at secondary and university level.

In questo lavoro si `e indagato il ruolo dell’autoefficacia e della confidenza sulla conoscenza di argomenti di base di fisica, dalla meccanica alla fisica moderna. Il campione era costituito da 142 femmine e 188 maschi. L’autoefficacia `e stata misurata con un questionario validato mediante analisi fattoriale confermativa con cinque dimensioni latenti: auto-regolazione; metacognizione; competenza percepita; coinvolgimento; ansia. La confidenza `e stata misurata con il grado di sicurezza nelle risposte date. I risultati mostrano un effetto indiretto dell’autoefficacia e uno diretto della confidenza sulla conoscenza in fisica. Si discuteranno effetti di genere e di motivazione.

In questo lavoro si sono analizzate mediante due scale Likert le attitudini verso la fisica ed i fisici di 330 studenti di liceo che partecipavano ad attività extracurriculari presso il Dipartimento di Fisica “E. Pancini” di Napoli. L’analisi `e basata sui metodi delle corrispondenze multiple e della clusterizzazione gerarchica. Si sono identificati 3 profili di studenti: a) entusiasti acritici della fisica (18%); b) ben disposti verso la fisica, accettata come strumento necessario per la società (67%); c) demotivati che considerano la fisica difficile e inutile (15%). Questi profili sono stati interpretati come “universi simbolici” che possono spiegare motivazione, autoefficacia e rendimento in fisica.

Phase-sensitive, spatially resolved optical second-harmonic-generation experiments were performed on LaAlO3/SrTiO3 heterostructures. Lateral inhomogeneities on a length scale of ≈ 30 μm are found when a one-unit-cell-thick epitaxial monolayer of LaAlO3 is grown on TiO2-terminated SrTiO3 single crystals. The inhomogeneity is absent in samples with LaAlO3 layers of more than one unit cell. The results are discussed in the framework of electronic, oxidic, and chemical inhomogeneities.

We report on the high resolution transmission electron microscopy (HRTEM) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) study of TiO2 anatase thin films grown by pulsed laser deposition on LaAlO3 substrates. The analysis provides evidence of a peculiar growth mode of anatase on LaAlO3 that is characterized by the formation of an epitaxial layer at the film/substrate interface. In particular, the film is split into two adjacent slabs of about 20 nm each, both displaying the same Bravais lattice compatible with the anatase tetragonal cell. The formation of two different families of crystallographic shear (CS) superstructures is observed within the film, namely (103)- and (101)-oriented CS plane structures, occurring in the outer film region and in proximity of the film/substrate interface, respectively. HAADF analysis and Energy Dispersive Spectroscopy highlight the occurrence of Al interdiffusion from the substrate into the film region. By combining HRTEM results, image simulation techniques and DFT calculations we determine the atomic structure of the CS planes, and show that they are cubic-TiO-based structures analogous to the TinO2n-1 Magnéli phases derived from rutile.

The polarization induced at the LaAlO3/SrTiO3 interface has been explored by optical second harmonic generation (SHG) spectroscopy. Our data reveal that an orbital reconstruction of the SrTiO3 surface occurs when three epitaxial monolayers of LaAlO3 are deposited on top of it. The reconstruction manifests as a spectral modification of a Ti4+(3d) state at the LaAlO3/SrTiO3 interface which is accompanied by a displacement of the Ti4+ ions in adjacent SrTiO3 monolayers in order to compensate for the polarization discontinuity induced at the interface. According to the SHG experiment, the carriers transferred to the interface are trapped because in spite of the orbital reconstruction, the interface remains insulating. The onset of conductivity with the formation of a two-dimensional electron liquid appears to be a subordinate effect related to a minority of carriers and occurs upon further increase of the LaAlO3 coverage.

In order to analyze the effect of strain on the magnetic properties of narrow-band manganites, temperature-and field-dependent susceptibilities of about 8.5-nm-thick epitaxial Pr(0.7)Ca(0.3)MnO(3) films, respectively, grown on (001) and (110) SrTiO(3) substrates, have been compared. For ultrathin samples grown on (001) SrTiO(3), a bulklike cluster-glass magnetic behavior is found, indicative of the possible coexistence of antiferromagnetic and ferromagnetic phases. On the contrary, ultrathin films grown on (110) substrates show a robust ferromagnetism with a strong spontaneous magnetization of about 3.4 mu(B)/Mn atom along the easy axis. On the base of high-resolution reciprocal space mapping analyses performed by x-ray diffraction, the different behaviors are discussed in terms of the crystallographic constraints imposed by the epitaxy of Pr(0.7)Ca(0.3)MnO(3) on SrTiO(3). We suggest that for growth on (110) SrTiO(3), the tensile strain on the film c axis, lying within the substrate plane, favors the ferromagnetic phase, possibly by allowing a mixed occupancy and hybridization of both in-plane and out-of-plane e(g) orbitals. Our data allow to shed some physics of inhomogeneous states in manganites and on the nature of their ferromagnetic insulating state.