Cecilia Blanco, M., J. M. De Paoli, S. Ceppi, G. Tirao, V. M. Nassif, J. Guimpel, and R. E. Carbonio. "Synthesis, structural characterization and magnetic properties of the monoclinic ordered double perovskites BaLaMSbO6, with MÂ =Â Mn, Co and Ni." Journal of Alloys and Compounds 606 (2014): 139–148.

Haberkorn, N., A. M. Condó, C. Espinoza, S. Jaureguizahar, J. Guimpel, and F. C. Lovey. "Bulklike behavior in the temperature driven martensitic transformation of CuZnAl thin films with 2H structure." Materials Letters 591 (2014): 263–267.

Zemma, E., J. Luzuriaga, and S. Babuin. "Analysis of motion of solid hydrogen tracer particles in oscillating superfluid flows." In Journal of Physics: Conference Series, 012029. Vol. 568., 2014.
Abstract: We have developed a relatively simple cryostat which allows us to image turbulent flows in superfluid helium at temperatures below 2 K, using frozen H2 particles. We analyze the statistics of the velocities of these solid tracers, which follow the turbulent flow generated by oscillating bodies. We have also studied one of the oscillators working in air at room temperature, and traced the flow with solid talcum particles for comparison. Images were recorded by a digital camera at 240 frames per second, while frequencies of the oscillators are between 20 to 45 Hz. The flow is characterized by a modified Reynolds number ReÎ´ based on the viscous penetration depth Î´. Software in a dedicated particle tracking velocimetry code allows us to compute the trajectories and velocities of tens of thousands of particles. We have obtained the number of particles for equally spaced intervals of the velocity modulus. For the oscillators in the superfluid, the probability of finding particles at higher velocities has an exponential decay. Within our resolution the statistics in the superfluid for oscillating objects with sharp borders is largely independent of ReÎ´, while the logarithmic decay at low velocities seems faster than for high velocities for rounded objects. On the other hand, for data taken in air the result is closer to a classical Gaussian distribution of velocities.

R. H. Rodriguez, L. Tosi, M. Menghini, H. Pastoriza and C. A. Balseiro. "Multiple First Order Transitions in Cr Thin Films." Journal of Physics: Conference Series 568, no. 4 (2014): 042031.
Abstract: The incommensurate spin density wave (SDW) in metalic Cr forms below T N = 311K and is characterized by a temperature dependent wavevector Q along the direction. The wavelength varies from 78 Ã… at 300 K to 60 Ã… at 150 K. In thin films, the Qvector orients perpendicular to the film surface and the SDW is forced to satisfy boundary conditions. As a consequence of the confinement, the SDW wavelength is quantized in a set of available modes, each one having n nodes. As the temperature decreases the wavelength does not follow a continuous bulktype variation but jumps between different allowed values. These jumps occur at certain determined temperatures T n as first order type transitions which are accompanied with a decrease ( n to n + 1 nodes) or an increase ( n + 1 to n nodes) of the resistance. In this work, we present transport measurements on Cr thin films showing hysteretic behavior in the resistance as a function of temperature in coolingwarming cycles. The hysteresis loops are thickness dependent and present structures which we associate with the possible multiple transitions that may occur as temperature is swept.

D. PerezMorelo and H. Pastoriza. "Torque magnetometry in YBa 2 Cu 3 O 7Î´ single crystals using high sensitive micromechanical torsional oscillator." Journal of Physics: Conference Series 568, no. 2 (2014): 022038.
Abstract: We have developed a highsensitive microtorsional oscillators and fabricated with a standard silicon process, as a platform to study the low temperatures magnetic properties of micron sized samples. When the oscillatorsample system interacts with a magnetic field, the displacement of the oscillator from its equilibrium position can be detected as a small change in the capacitance (â‰ˆ 0.001 pF). We use this device to study the magnetic response of a thick twinned YBa 2 Cu 3 O 7âˆ’ Î´ disk when the magnetic field is tilted away from the c axis in the temperature range 80 K < T < 100 K (T c â‰ˆ 92K).

M. I. Dolz, Y. Fasano, N. R. Cejas Bolecek, H. Pastoriza, M. Konczykowski and C. J. van der Beek. "Detection of discretized singleshell penetration in mesoscopic vortex matter." Journal of Physics: Conference Series 568, no. 2 (2014): 022010.
Abstract: We investigated configurational changes in mesoscopic vortex matter with less than thousand vortices during flux penetration in freestanding 50 Î¼m diameter disks of Bi 2 Sr 2 CaCu 2 O 8+Î´ . Highresolution AC and DC local magnetometry data reveal oscillations in the transmittivity echoed in peaks in the thirdharmonics magnetic signal fainting on increasing vortex density. By means of extra experimental evidence and a simple geometrical analysis we show that these features fingerprint the discretized entrance of singleshells of vortices having a shape that mimics the sample edge.

Amigó, M. L., V. A. Crivillero, D. G. Franco, A. BadíaMajós, J. Guimpel, and G. Nieva. "Vortex pinning by intrinsic correlated defects in Fe<inf>1y</inf>Se." Journal of Physics: Conference Series 507, no. Part 1 (2014).

Schmoranzer, D., M. J. Jackson, and J. Luzuriaga. "On the Nonlinear Damping of Mechanical Oscillators in Flows of 4He." Journal of Low Temperature Physics 175, no. 1 (2014): 97–103.
Abstract: In the studies of both classical and quantum turbulence, significant attention is devoted to the investigation of the behavior of various submerged resonators. Upon entering the turbulent regime, the oscillators start to experience a significant drag force, which varies nonlinearly with velocity. We present an empirical way of modeling such systems, and calculate the expected resonant response of such oscillators near the fundamental frequency as a function of the applied driving force. We apply the model to the crossover from linear to nonlinear drag forces and compare with previous models as well as selected experimental data on the transition to turbulence in oscillatory flow of 4He.

Espinoza Torres, C., A. M. Condó, N. Haberkorn, E. Zelaya, D. Schryvers, J. Guimpel, and F. C. Lovey. "Structures in textured CuAlNi shape memory thin films grown by sputtering." Materials Letters 96 (2014): 256–262.

M. I. Dolz, Y. Fasano, H. Pastoriza, V. Mosser, M. Li, M. Konczykowski. "Latentheat and nonlinear vortex liquid at the vicinity of the firstorder phase transition in layered highTc superconductors." Physical Review B (Condensed Matter and Materials Physics) 90, no. 14 (2014): 144507.
Abstract: In this work we revisit the vortex matter phase diagram in layered superconductors solving still open questions by means of ac and dc local magnetic measurements in the paradigmatic Bi2Sr2CaCu2O8 compound. We show that measuring with ac magnetic techniques is mandatory in order to probe the bulk response of vortex matter, particularly at high temperatures where surface barriers for vortex entrance dominate. From the TFOT evolution of the enthalpy and latent heat at the transition we find that, contrary to previous reports, the nature of the dominant interlayer coupling is electromagnetic in the whole temperature range. By studying the dynamic properties of the phase located at Tâ‰³TFOT, we reveal spanning in a considerable fraction of the phase diagram of a nonlinear vortex phase suggesting that bulk pinning might play a role even in the liquid vortex phase.
