Una tarde con Ramón. Entrevista a Ramón Valdés

Aquesta entrevista al Catedràtic Emèrit de la UAB, Dr. Ramón Valdés del Toro, la van realitzar l'11 de juliol de 2006 un grup d'alumnes de l'assignatura Etnologia Regional que es va impartir el curs 2005-06 a la Llicenciatura d'Antropologia Social d'aquesta universitat. L'entrevista forma part d'un projecte més ampli vinculat a l'assignatura dirigit per la professora que l'imparteix, Montserrat Clua i Fainé.Esta entrevista al Catedrático Emérito de la UAB, Dr. Ramón Valdés del Toro, fue realizada el 11 de julio de 2006 por un grupo de alumnas de la asignatura Etnología Regional que se impartió el curso 2005-06 en la Licenciatura de Antropología Social de dicha universidad. La entrevista forma parte de un proyecto más amplio vinculado a la asignatura y dirigido por su profesora, Montserrat Clua i Fainé

Determination of the local structure of Sr2−x_{2-x}Mx_xIrO4_4 (M = K, La) as a function of doping and temperature

The local structure of correlated spin-orbit insulator Sr$_{2-x}$M$_x$IrO$_4$ (M = K, La) has been investigated by Ir L$_3$-edge extended x-ray absorption fine structure measurements. The measurements were performed as a function of temperature for different dopings induced by substitution of Sr with La or K. It is found that Ir-O bonds have strong covalency and they hardly show any change across the N\'eel temperature. In the studied doping range, neither Ir-O bonds nor their dynamics, measured by their mean square relative displacements, show any appreciable change upon carrier doping, indicating possibility of a nanoscale phase separation in the doped system. On the other hand, there is a large increase of the static disorder in Ir-Sr correlation, larger for K doping than La doping. Similarities and differences with respect to the local lattice displacements in cuprates are briefly discussed.Comment: Main text: 6 pages, 4 figures, Supplemental information: 2 pages, 2 figure

Charge density wave in layered La1-xCexSb2

The layered rare-earth diantimonides RSb2 are anisotropic metals with generally low electronic densities whose properties can be modified by substituting the rare earth. LaSb2 is a nonmagnetic metal with a low residual resistivity presenting a low-temperature magnetoresistance that does not saturate with the magnetic field. It has been proposed that the latter can be associated to a charge density wave (CDW), but no CDW has yet been found. Here we find a kink in the resistivity above room temperature in LaSb2 (at 355 K) and show that the kink becomes much more pronounced with substitution of La by Ce along the La1−xCexSb2 series. We find signatures of a CDW in x-ray scattering, specific heat, and scanning tunneling microscopy (STM) experiments in particular for x ≈ 0.5. We observe a distortion of rare-earth–Sb bonds lying in-plane of the tetragonal crystal using x-ray scattering, an anomaly in the specific heat at the same temperature as the kink in resistivity and charge modulations in STM. We conclude that LaSb2 has a CDW which is stabilized in the La1−xCexSb2 series due to substitutional disorderThis work was supported by the Spanish MINECO (FIS2014-54498-R, MAT2011-27470-C02-02, and CSD-2009-00013), by the European Union (Graphene Flagship Contract No. CNECT-ICT-604391 and COST MP1201 action), and by the Comunidad de Madrid through programs Nanofrontmag-CM (S2013/MIT-2850) and MAD2D-CM (S2013/MIT-3007).We acknowledge MINECO and CSIC for financial support and for provision of synchrotron radiation facilities and would like to thank the SpLine BM25 staff for assistance in using the beamlin

Temperature-dependent local structure and superconductivity of BaPd2As2 and SrPd2As2

The local structures of 122-type paradium arsenides, namely BaPd2As2 and SrPd2As2, are examined by As K-edge extended x-ray absorption fine structure measurements to find a possible correlation between the variation of their superconducting transition temperature and the local structure. The local atomic distances are found to be consistent with average distances measured by diffraction techniques. The temperature dependence of mean square relative displacements reveal that, while BaPd2As2 is characterized by a local As-Pd soft mode, albeit with larger atomic disorder, SrPd2As2 shows anomalous As-Pd correlations with a kink at similar to 160 K due to hardening by raising temperature. We have discussed implications of these results and possible mechanisms of differing superconducting transition temperature in relation with the structural instability

Una tarde con Ramón. Entrevista a Ramón Valdés

Aquesta entrevista al Catedràtic Emèrit de la UAB, Dr. Ramón Valdés del Toro, la van realitzar l'11 de juliol de 2006 un grup d'alumnes de l'assignatura Etnologia Regional que es va impartir el curs 2005-06 a la Llicenciatura d'Antropologia Social d'aquesta universitat. L'entrevista forma part d'un projecte més ampli vinculat a l'assignatura dirigit per la professora que l'imparteix, Montserrat Clua i Fainé.Esta entrevista al Catedrático Emérito de la UAB, Dr. Ramón Valdés del Toro, fue realizada el 11 de julio de 2006 por un grupo de alumnas de la asignatura Etnología Regional que se impartió el curso 2005-06 en la Licenciatura de Antropología Social de dicha universidad. La entrevista forma parte de un proyecto más amplio vinculado a la asignatura y dirigido por su profesora, Montserrat Clua i Fainé

Correlated effects of fluorine and hydrogen in fluorinated tin oxide FTO transparent electrodes deposited by sputtering at room temperature

The optical and electrical properties of fluorinated tin oxide (FTO) films deposited at room temperature by sputtering have been investigated varying the fluorine content and the hydrogen atmosphere. The complex behavior of the obtained films is disclosed using a wide set of characterization techniques that reveals the combined effects of these two parameters on the generated defects. These defects control the electrical transport (carrier density, mobility and conductivity), the optical properties (band gap and defects-related absorption and photoluminescence) and finally promote the amorphization of the samples. H2 in the sputtering gas does not modify the H content in the films but induces the partial reduction of tin (from Sn4 to Sn2) and the consequent generation of oxygen vacancies with shallow energy levels close to the valence band. A variation of up to four orders of magnitude in electrical conductivity is reported in samples with the appropriate fluorine doping and hydrogen fraction in the sputtering gas, maintaining excellent optical transparency. Optimized room temperature grown electrodes reach sheet resistance ~20 Omega and transparency 90%. This room temperature deposition process enables film preparation on flexible organic substrates, such as polyethylene terephthalate (PET), with identical performance of doubtless interest in flexible and large scale electronics.We would like to thank IDIVAL for financial support, Projects N°NVAL16/17, INNVAL19/18 and NVAL18/07. CRL thanks the MINECO for the Juan de la Cierva Formación grant (ref. FJCI-2015-25306). This work has been supported by the Spanish MINECO, Instituto de Salud Carlos III, the European Union FEDER funds under Projects ref. PI16/00496 (AES 2016), PI19/00349 and DTS19/00033 (AES 2019). The authors are grateful to Dr F Madrazo and the Laser Microscopy Unit of the IDIVAL Institute for the use of the Confocal Raman Imaging Microscope

CareTrack: assessing the appropriateness of health care delivery in Australia

OBJECTIVE: To determine the percentage of health care encounters at which a sample of adult Australians received appropriate care (ie, care in line with evidence-based or consensus-based guidelines). DESIGN, SETTING AND PARTICIPANTS: Computer-assisted telephone interviews and retrospective review of the medical records (for 2009-2010) of a sample of at least 1000 Australian adults to measure compliance with 522 expert consensus indicators representing appropriate care for 22 common conditions. Participants were selected from households in areas of South Australia and New South Wales chosen to be representative of the socioeconomic profile of Australians. Health care encounters occurred in health care practices and hospitals with general practitioners, specialists, physiotherapists, chiropractors, psychologists and counsellors. MAIN OUTCOME MEASURE: Percentage of health care encounters at which the sample received appropriate care. RESULTS: From 15 292 households contacted by telephone, 7649 individuals agreed to participate, 3567 consented, 2638 proved eligible, and 1154 were included after gaining the consent of their health care providers. The adult Australians in this sample received appropriate care at 57% (95% CI, 54%-60%) of 35 573 eligible health care encounters. Compliance with indicators of appropriate care at condition level ranged from 13% (95% CI, 1%-43%) for alcohol dependence to 90% (95% CI, 85%-93%) for coronary artery disease. For health care providers with more than 300 eligible encounters each, overall compliance ranged from 32% to 86%. CONCLUSIONS: Although there were pockets of excellence and some aspects of care were well managed across health care providers, the consistent delivery of appropriate care needs improvement, and gaps in care should be addressed. There is a need for national agreement on clinical standards and better structuring of medical records to facilitate the delivery of more appropriate care.William B Runciman, Tamara D Hunt, Natalie A Hannaford, Peter D Hibbert, Johanna I Westbrook, Enrico W Coiera, Richard O Day, Diane M Hindmarsh, Jeffrey Braithwait

Local disorder and structure relation induced by magnetic exchange interactions in A2(Mo1-yMny)2O7 pyrochlores

We present an extended X-ray absorption fine structure study at the Mo K-edge of A2(Mo1yMny)2O7 (A Gd, Ho; y 0.05 and 0.10) pyrochlores, as a function of temperature and composition, coupled to diffractometric and magnetic characterizations. Extending the study reported in our previous paper on the pristine A2Mo2O7 compounds to these Mo/Mn partially substituted samples, where we hypothesize a competition between double-exchange and superexchange couplings, we aim to check which structure parameters are related to the nature of the nearest-neighbor magnetic interactions, looking for the presence and evolution of order and structure anomalies. Two Ho samples Ho2(Mo1yMny)2O7 (y 0.05 and 0.10) keep the spin-glass nature of the parent compositions with a strong distortion of the MoO(1)6 octahedron and of the MoHo and MoMo second shell. On the other hand, two Gd2(Mo1yMny)2O7 samples, ferromagnetic at low temperature in the undoped case, show the appearance on a local scale of a spin-glass transition mirrored by a quite high structure disorder and by a distortion coherent with a lattice frustration after Mn-doping. Therefore, the Gd and Ho Mn-doped samples display a similar frustrated behavior, differently from the corresponding undoped ones.We gratefully acknowledge the Spanish CRG at the ESRF for providing beamtime under experiment HC-3343. MS thanks Prof. Monica Dapiaggi for useful discussions. GL thanks Prof. Fabio M. Canepa for illuminating discussions. F.R.-M. gratefully acknowledge the support of the AEI (Spanish Government) Project (No. MAT2017-86450-C4-1-R). F.R.-M. is indebted to MINECO for the Ramon y Cajal contract (Ref: RyC-2015-18626), which is co-financed by the European Social Fund

Local disorder and structure relation induced by magnetic exchange interactions in A2(Mo1 12yMny)2O7 pyrochlores

We present an extended X-ray absorption fine structure study at the Mo K-edge of A2(Mo1 12yMny)2O7 (A = Gd, Ho; y = 0.05 and 0.10) pyrochlores, as a function of temperature and composition, coupled to diffractometric and magnetic characterizations. Extending the study reported in our previous paper on the pristine A2Mo2O7 compounds to these Mo/Mn partially substituted samples, where we hypothesize a competition between double-exchange and superexchange couplings, we aim to check which structure parameters are related to the nature of the nearest-neighbor magnetic interactions, looking for the presence and evolution of order and structure anomalies. Two Ho samples Ho2(Mo1 12yMny)2O7 (y = 0.05 and 0.10) keep the spin-glass nature of the parent compositions with a strong distortion of the MoO(1)6 octahedron and of the Mo\u2012Ho and Mo\u2012Mo second shell. On the other hand, two Gd2(Mo1 12yMny)2O7 samples, ferromagnetic at low temperature in the undoped case, show the appearance on a local scale of a spin-glass transition mirrored by a quite high structure disorder and by a distortion coherent with a lattice frustration after Mn-doping. Therefore, the Gd and Ho Mn-doped samples display a similar frustrated behavior, differently from the corresponding undoped ones