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Based on constructivism and cognitivism we believe that learning physics in schools can be faced as a process of reshaping students’ mental models about Nature’s behavior. These can correlate with existing physics misconceptions. Aware of the negative consequences of basic cognitive misunderstandings and believing that their correction, implying active and motivated students, should start from first contacts with physics knowledge in lower secondary schools, we asked three schoolteachers to participate on a pilot study with 7th, 8th and 9th graders. This study is specifically designed to promote and coach teachers’ attitudinal changes towards stronger student centered teaching behaviors. We report results obtained during academic year 2017/2018, some qualitative (from teachers diaries and recorded interviews) and a quantitative quasi-experimental study (with pre- and post-tests and control groups) with 9th graders, searching for misconceptions evolution on basic mechanics. The results obtained with 15 out of the 30 questions of the Force Concept Inventory indicate a fairly high average normalized gain for the experimental group. However, this average gain was not uniformly distributed along every FCI question, evidencing some difficulties with Newton’s 3rd law understanding. A recommended approach for its teaching in 2018/2019 produced evidence of deep learning of every tested mechanics concept.

A single-crystal synchrotron radiation study of gadolinium selenide has been made in the temperature range 15 - 100 K. GdSe has the rocksalt structure and becomes antiferromagnetic below a reported Neel temperature of 65 K. At 15 K, magnetic reflections are observed at with modulation wavevector propagating from reciprocal lattice point G. This is achieved by exploiting the resonant enhancement in the vicinity of the and edges. Similar enhancements are observed at the two edges, with the maximum effect occurring approximately 3 eV above the absorption edge. The temperature dependence of the intensity of the magnetic reflections indicates a Neel temperature of 63(1) K. These measurements, together with high-resolution studies of the fundamental reflections , contribute further evidence of magnetic or structural changes in the sample at 37(1) K. Our observations are discussed and compared with previous x-ray diffraction and magnetic susceptibility measurements.

X-ray diffraction patterns of equimolecular concentrated aqueous solutions of yttrium chloride and bromide have been investigated from s=0.4 AA-1 up to s=15 AA-1. An assumed coordination of eight water molecules around each yttrium cation, at a distance of 2.36 AA, reproduces the intensity at high s values in agreement with the values obtained by some of the present authors from EXAFS experiments. Narrow interference maxima at s=(4 pi sin theta )/ lambda approximately=0.9 AA-1 may be interpreted as the existence of a local order of the hydrated yttrium cations surrounded by anions and free water molecules. Structural models with and without close packing of the hydrated cations were built to simulate that local order.

Polarised neutron scattering measurements have been made on single crystals of FeF2. The observation of a polarisation-dependent cross section for mixed magnetic and nuclear reflections showed that the two types of antiferromagnetic domains were unequally populated. Integrated intensity measurements were fitted to an extinction model which enabled the domain population to be established quantitatively. Moduli of the magnetic interaction vectors were deduced from polarisation ratio measurements of both mixed magnetic and nuclear and 'forbidden' magnetic reflections. The former were compared with those calculated on an ionic model using the wavefunction deduced from resonance studies and the parameters of this wavefunction were fitted to the higher-angle measurements. Deviation of the lower-angle reflections from this model were interpreted as evidence of covalency and gave a value of 0.049(10) for the sum of the covalency parameters. By comparing the experimental structure factors for the forbidden reflections with those calculated for a covalent wavefunction, individual covalent mixing parameters could be estimated.