Thermally activated dynamics of the tilts of the CuO6 octahedra, hopping of interstitial O, and possible instability towards the LTT phase in La2CuO4+δ

The anelastic spectrum (dynamic Young's modulus and elastic energy absorption) of La2CuO4+δ has been measured between 1 and 700 K with 0<δ<0.02. The spectrum of stoichiometric La2CuO4 in the low-temperature orthorhombic (LTO) phase is dominated by two intense relaxation processes which cause softenings of 16% around 150 K and 9% below 30 K at f∼1 kHz. The relaxation at 150 K is attributed to the presence of a fraction of the CuO6 octahedra which are able to change their tilted configuration by thermal activation between orientations which are nearly energetically equivalent, possibly within the twin boundaries. The relaxation below 30 K is governed by tunneling, and involves a considerable fraction of the lattice atoms. It is proposed that the double-well potentials for the low-temperature relaxation are created by the tendency of the LTO phase to form low-temperature tetragonal (LTT) domains, which however are not stabilized like when La is partially substituted with Ba. On doping with excess O, the relaxation rates of these processes are initially enhanced by hole doping, while their intensities are depressed by lattice disorder; an explanation of this behavior is provided. Excess O also causes two additional relaxation processes. The one appearing at lower values of δ is attributed to the hopping of single interstitial O2- ions, with a hopping rate equal to τ-1=2×10-14exp(-5600/T) s. The second process is slower and can be due to O pairs or other complexes containing excess O.

The instability of the emerging-market assets demand schedule

Includes bibliography

Growth, instability and the convertibility crisis in Argentina

Includes bibliography

Towards an integrated vision for dealing with instability and risk

Includes bibliography

Income instability, mobility and distribution in Argentina

Includes bibliography

The "China effect" on commodity prices and Latin American export earnings

Includes bibliography

Ferroelectric and structural instability of (Pb,Ca)TiO3 thin films prepared in an oxygen atmosphere and deposited on LSCO thin films which act as a buffer layer

Structural, microstructural and ferroelectric properties of Pb0.90Ca0.10TiO3 (PCT10) thin films deposited using La0.50Sr0.50CoO3 (LSCO) thin films which serve only as a buffer layer were compared with properties of the thin films grown using a platinum-coated silicon substrate. LSCO and PCT10 thin films were grown using the chemical solution deposition method and heat-treated in an oxygen atmosphere at 700 °C and 650 °C in a tube oven, respectively. X-ray diffraction (XRD) and Raman spectroscopy results showed that PCT10 thin films deposited directly on a platinum-coated silicon substrate exhibit a strong tetragonal character while thin films with the LSCO buffer layer displayed a smaller tetragonal character. Surface morphology observations by atomic force microscopy (AFM) revealed that PCT10 thin films with a LSCO buffer layer had a smoother surface and smaller grain size compared with thin films grown on a platinum-coated silicon substrate. Additionally, the capacitance versus voltage curves and hysteresis loop measurement indicated that the degree of polarization decreased for PCT10 thin films on a LSCO buffer layer compared with PCT10 thin films deposited directly on a platinum-coated silicon substrate. This phenomenon can be described as the smaller shift off-center of Ti atoms along the c-direction 〈001〉 inside the TiO6 octahedron unit due to the reduction of lattice parameters. Remnant polarization (P r ) values are about 30 μC/cm2 and 12 μC/cm2 for PCT10/Pt and PCT10/LSCO thin films, respectively. Results showed that the LSCO buffer layer strongly influenced the structural, microstructural and ferroelectric properties of PCT10 thin films. © 2013 Elsevier Ltd and Techna Group S.r.l.

Political instability, institutional quality and social conflict in the Andes

Includes bibliography

Impact of Internet use on individual earnings

Includes bibliography

The earnings share of total income in Latin America, 1990-2010

This article analyses the share of total income represented by employment earnings in the countries of Latin America over the last two decades. It first considers the wage share of gross domestic product (gdp) and then adds in the earnings of self-employed workers. The findings indicate that both total wages and total earnings declined as a share of gdp in most of the region’s countries over the period, although there were some exceptions. The reduction in earnings inequality seen over the past decade was not usually accompanied by an increase in the gdp share of earnings. This means that the improvement in personal income distribution was not matched by an improvement in functional distribution.

Index of political instability in Brazil, 1889-2009

This article aims to develop an index of political instability (ins) in Brazil between 1889 and 2009, reflecting a wide-ranging set of multiple phenomena that represent conflicts between the different social groups. By presenting different definitions of what is understood by political instability in the economics literature and by using multiple historical events —coups d’état, civil conflicts, constitutional or unconstitutional overthrow and changes in the composition of 50% of the ministerial cabinet— different indicators are obtained which are then synthesized into a single index using the principal component technique, to obtain an ins for Brazil between 1889 and 2009.

CEPAL Review no. 114

Aspects of recent developments in the Latin American and Caribbean labour markets / Jürgen Weller .-- The earnings share of total income in Latin America, 1990-2010 / Martín Abeles, Verónica Amarante and Daniel Vega .-- Latin America: Total factor productivity and its components / Jair Andrade Araujo, Débora Gaspar Feitosa and Almir Bittencourt da Silva .-- Financial constraints on economic development: Theory and policy for developing countries / Jennifer Hermann .-- The impact of China’s incursion into the North American Free Trade Agreement (NAFTA) on intra-industry trade / Jorge Alberto López A., Óscar Rodil M. and Saúl Valdez G. .-- Work, family and public policy changes in Latin America: Equity, maternalism and co-responsibility / Merike Blofield and Juliana Martínez F. .-- A first approach to the impact of the real exchange rate on industrial sectors in Colombia / Lya Paola Sierra and Karina Manrique L. .-- Global integration, disarticulation and competitiveness in Mexico’s electromechanical sector: A structural analysis / Raúl Vázquez López .-- Technological capacity-building in unstable settings: Manufacturing firms in Argentina and Brazil / Anabel Marín, Lilia Stubrin and María Amelia Gibbons .-- Index of political instability in Brazil, 1889-2009 / Jaime Jordan Costantini and Mauricio Vaz Lobo Bittencourt

Genetic Instability Persists in Non-Neoplastic Urothelial Cells from Patients with a History of Urothelial Cell Carcinoma

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)