Young Researcher Seminar

Seminar of the Young Researchers at INC.

This meeting is weekly organized by young researchers at Nicolas Cabrera Institute and informs the audience about the updates in their research projects. Meeting is followed by an informal discussion session where Researchers address the querries and also receive feedback enabling them to strengthen their talks.

Where: Conference Room, Modulo VIII 4th Floor.

Next meetings: To be announced.

Previous meetings: 

17. Title: “Synthesis and characterization of single crstal Bi(3)Ni”  

Blanca Silva Fernandez, LBT UAM

Abstract: In the last years, Bi(3)Ni has been studied by various groups to study the co-existence of superconducting and ferromagnetic correlations. In our work, we grow single crystals of Bi(3)Ni by the flux excess method. We study the superconducting and the magnetic properies of our samples, and conclude that the magnetic component found in the superconducting state is due to Ni inclusions or grain grain boundaries.

Friday 22 Mar 2013 12.00-12.30 pm 

16. Title: “Heavy fermion phases probed by temperature dependent tunneling spectroscopy”  

A. Maldonado, LBT UAM

Abstract: Heavy fermions offer a rich physical phenomenology at very low temperatures, exhibiting different phase transitions on cooling that determine their electronic properties. Their ground states cover many electronic interactions, such as Kondo effect, superconducting or long range magnetic ones and, eventually, their coexistence. Thus, exploring the local electronic properties of these systems using scanning tunneling microscopy/spectroscopy (STM/S) at different temperatures is essential. In this communication, tunneling spectroscopy measurements using a superconducting tip of Al in the superconducting phase of URu2Si2 [1] and using one of Au in the paramagnetic and antiferromagnetic phases of, respectively, CeRu2Si2 and CeRh2Si2 [2] will be discussed. The features found in the tunneling spectroscopy of each compound at 0.15 K and their respective thermal evolution reflect the formation of different electronic ground states.

Ref: [1] A. Maldonado et al., Phys. Rev. B 85, 214512 (2012). [2] A. Maldonado et al., J. Phys.:Condens. Matter 24, 475602 (2012).

Friday 15 Mar 2013 1.20-1.30 pm 

15. Title: “Paramagnetic Meissner Effect in conventional superconductors: New observations at low field magnetization in single crystal, Nb and Stannides(Ca,Yb) ”  

P. Kulkarni, LBT UAM

Abstract: In this talk, I will present new observations pertaining to the magnetization at the onset of the superconducting state in single crystals of Niobium (Nb), Ca3Rh4Sn13 and Yb3Rh4Sn13.

Friday 15 Mar 2013 1.00-1.20 pm 

14. Title: “Structure and Dynamics of Epitaxial Graphene on Ir(111) Studied by Means of Helium Atom Scattering”  

Amjad Al Taleb, UAM

Abstract: Helium Atom Scattering (HAS) is an important technique for investigating the structure and dynamics of solid surfaces. Because of the low energies employed (ca. 100 meV), neutral He atoms probe the topmost surface layer of any material in an inert, completely non-destructive manner. They can be equally used to investigate insulating or conducting materials as well as fragile samples, which are difficult to examine by other methods because of sample charging or electron excitation effects. We have applied this technique to study the structure and phonon dynamics of graphene epitaxially grown on Ir(111). By measuring He-diffraction spectra and the reflectivity of the incoming helium beam on the graphene/Ir(111) surface we have determined the parameters of the He-surface interaction potential as well as the corresponding phonon dispersion curves.

Friday 22 Feb 2013 1.00-1.30 pm

13. Title: “Direct observation of superconducting vortices in the heavy fermion compound CeCu2Si2”  

Ana Maldonado, LBT UAM

Abstract: There is a large number of heavy fermion superconductors and this number has increased significantly in the last 30 years. Nevertheless, the characterization of such phase using a scanning probe technique remains challenging due to the low temperatures and energy scales required. In this talk, I will focus on the characterization of the superconducting state of the first heavy fermion superconductor discovered, CeCu2Si2, by scanning tunneling microscopy/spectroscopy (STM/S) at very low temperatures. The experiments were performed during my recent stay of three months in the group headed by Dr. Peter Wahl in Max-Planck Institute in Stuttgart, Germany.

Friday 15 Feb 2013 1.00-1.30 pm

12. Title: “Nature of the magnetic coupling in Co/MnF2 bilayers: Combined studies by using VT v-KERR and XMCD ”  

Jose Luis Cuñado, UAM

Abstract: We present a detailed study of temperature dependence of magnetization reversal properties in artificial magnetic nanostructures, by using a new experimental set-up that allows us to measure simultaneously magneto-resistance and vectorial-Kerr hysteresis loops at full angular range of the applied field angle, and in a broad temperature range (4 K to 500 K). Co/MnF2 bilayers have been studied using this device. New exchange bias phenomena at room temperature have been found, in particular, field-induced exchange bias above the MnF2 Neel temperature. Comparison with element-sensitive XCMD measurements is made to confirm  the  observed exchange bias behavior.

Friday 30 Nov 2012    1.00-1.30 pm

11. Title: “Finding the conducting needle in the insulating barn”      

Aday Molina LBT UAM

Abstract: Molecular electronics is an important line of research in the nanotechnology field. In order to study electric and magnetic properties of molecules, we are interested on creating single-molecule junctions with the skill of manipulate the energetic levels of the molecule with a gate voltage. To do so, we work with samples which have three layers: semiconductor-insulator-graphene; we have developed a technique based on difference of capacitance measurements to find small electrodes over insulating surfaces and, after finding the electrode, we are able to do STM on it. In this seminar, I will explain the technique and how we plan to use it for creating single-molecule junctions.

Friday 23 Nov 2012     1.00-1.20 pm

10. Low temperature studies in single crystal HoBi  

Antón Hernández LBT UAM

I will present my experience in the Ames Lab trying to give an idea what I have learned in my stay there. I will also show our results of the low temperature study of HoBi.

Friday 26 Oct 2012      1.00-1.20 pm 

9. STM studies on DyW30

Siya Sherif  LBT UAM

Abstract:Information technology is partly based on magnetism (memory) and partly on electricity (processors). Increasing control over individual electron charges and spins provides new device functionality. For both charges and spins, molecular devices provide ideal test beds. In this talk, I will discuss about the technical details addressing single molecule magnets using STM and early results with the Polyoxometalate, DyW30.

Friday 19 Oct 2012      1.00-1.25 pm.

8. Understanding electron and heat transport through one and two C60 molecules bridging gold electrodes – Theory and experiment

Charalambos Evangeli LBT UAM 

Friday 22 June 2012  

7. Magneto Caloric Effect and its Applications

Jan Hanko. Laboratorio de Bajas Temperaturas UAM.

Friday 01 June 2012

6. Study of the Flux Line Lattice in YBa2Cu3O7 by Magnetic Decoration

Roberto F. Luccas. Laboratorio de Bajas Temperaturas UAM.

Friday 25 May 2012

5. Diamond anvil cells

Manuel Rodríguez Osorio. Laboratorio de Bajas Temperaturas UAM.

Friday 18 May 2012

4. Superconductor to insulator transition, electronic charge modulations and co-existence of superconducting and insulating phases in thin film of TiN

Prasanna Kulkarni. Laboratorio de Bajas Temperaturas UAM.

Friday 4 May 2012

3. Low temperature properties of a geological galss

Tómas Perez. Laboratorio de Bajas Temperaturas UAM.

Friday 27 April 2012  

2. Interplay between Kondo effect and antiferromagnetism probed by scanning tunneling spectroscopy 

Ana Maldonado. Laboratorio de Bajas Temperaturas UAM.

Friday 20 April 2012

1. Scanning Tunneling Microscopy in Layered Superconductors

Jose Augusto Galvis. Laboratorio de Bajas Temperaturas UAM.

Friday 13 April 2012 


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