Temperature dependence of the excitation spectrum in the charge-density-wave ErTe3_3 and HoTe3_3 systems

We provide optical reflectivity data collected over a broad spectral range and as a function of temperature on the ErTe$_3$ and HoTe$_3$ materials, which undergo two consecutive charge-density-wave (CDW) phase transitions at $T_{CDW1}$= 265 and 288 K and at $T_{CDW2}$= 157 and 110 K, respectively. We observe the temperature dependence of both the Drude component, due to the itinerant charge carriers, and the single-particle peak, ascribed to the charge-density-wave gap excitation. The CDW gap progressively opens while the metallic component gets narrow with decreasing temperature. An important fraction of the whole Fermi surface seems to be affected by the CDW phase transitions. It turns out that the temperature and the previously investigated pressure dependence of the most relevant CDW parameters share several common features and behaviors. Particularly, the order parameter of the CDW state is in general agreement with the predictions of the BCS theory

The Physical Anthropology of Pottery Mound: A Pueblo IV Site in West Central New Mexico

The thesis presents the anthropometric data on 110 skeletons obtained by the University of New Mexico from Pueblo IV site of Pottery Mound. The measurements include 27 dimensions and 11 indices of the skull, face, and long bones of all or part of the 49 individuals. Observations on pathologist of the bones and teeth are also discussed. These data are compared with similar material from the Pueblo IV sites of Paako, Pecos, and Hawikuh. The Pottery Mound materials, although of a general Southwestern physical type, are somewhat divergent from other Pueblo IV groups

GROWTH, DEVELOPMENT AND FOLIARY ULTRASTRUCTURAL PARAMETERS OF DIFFERENT EUCALYPTUS GENETIC MATERIALS

Currently eucalyptus is used as raw material in different industrial segments. The aim of this study was to evaluate the growth, development and ultrastructural parameters in different eucalyptus genetic materials. The randomized block experiment was carried out in ten treatments and five replicates, with different genetic materials: six hybrids:I-144; H-13; 110; NA-151; NA-189 (Eucalyptus urophilla S. T. Blake x Eucalyptus grandis W. Hill); Grancam 1277 (Eucalyptus grandis W. Hill x Eucalyptus camaldulensis Dehnh.); and four pure genetic materials:0020 (Eucalyptus saligna Sm.); 0010 (Eucalyptus resinífera Sm.); Eucalyptus pellita F. Muell. and Corymbia torelliana (F. Muell.) K. D. Hill & L. A. S. Johnson.Approximately four years after planting, the following variables were determined: plant height (AP), diameter at breast height (DAP), spad index (ISPAD), adaxial cuticle thickness (ECAD), abaxial cuticle thickness (ADX), abaxial epidermal thickness (EEAB), xylem diameter (DX), phloem diameter (DF) and palisade parenchyma length (CPP).The materials NA - 151 (Eucalyptus urophilla x E. grandis) and Grancam 1277 (E. grandis x E. camaldulensis) presented higher plant height (AP). The materials 0020 (E. saligna); 0010 (E. resinífera) and Corymbia torelliana presented smaller diameter at breast height (DAP). In general, the Corymbia torelliana genetic material had the lowest values in the ultrastructural foliar parameter

Origin of the ϕ ∼ ±9° peaks in YBa2Cu3O7−δ films grown on cubic zirconia substrates

The c-axis oriented YBa2Cu3O7−δ films grown on (001) yttria-stabilized cubic zirconia (YSZ) substrates often contain domains whose in-plane alignment is rotated approximately 9° from the cube-on-cube epitaxial relationship, in addition to the more commonly observed 0° and 45° in-plane rotations. We have investigated the origin of this ∼9° orientation using in situ electron diffraction during growth and ex situ 4-circle x-ray diffraction. Our results indicate that the ∼9° orientation provides the most favorable lattice match between the interfacial (110)-oriented BaZrO3 epitaxial reaction layer, which forms between YBa2Cu3O7−δ and the YSZ substrate. If epitaxy occurs directly between YBa2Cu3O7−δ and the YSZ substrate, i.e., before the BaZrO3 epitaxial reaction layer is formed, the 0° and 45° domains have the most favorable lattice match. However, growth conditions that favor the formation of the BaZrO3 reaction layer prior to the nucleation of YBa2Cu3O7−δ lead to an increase in ∼9° domains. The observed phenomenon, which results from epitaxial alignment between the diagonal of a square surface net and the diagonal of a rectangular surface net, is a general method for producing in-plane misorientations, and has also been observed for the heteroepitaxial growth of other materials, including (Ba, K)BiO3/LaAlO3. The YBa2Cu3O7−δ/YSZ case involves epitaxial alignment between [111]BaZrO3 and [110]YSZ, resulting in an expected in-plane rotation of 11.3° to 9.7° for fully commensurate and for fully relaxed (110)BaZrO3 on (001)YSZ, respectivel

Magnetic structure and phase diagram of the Heisenberg-Ising spin chain antiferromagnetic PbCo2_{2}V2_{2}O8_{8}

The effective spin-1/2 antiferromagnetic Heisenberg-Ising chain materials, ACo$_2$V$_2$O$_8$, A = Sr, Ba, are a rich source of exotic fundamental phenomena and have been investigated for their model magnetic properties both in zero and non-zero magnetic fields. Here we investigate a new member of the family, namely PbCo$_2$V$_2$O$_8$. We synthesize powder and single crystal samples of PbCo$_2$V$_2$O$_8$ and determine its magnetic structure using neutron diffraction. Furthermore, the magnetic field/temperature phase diagrams for magnetic field applied along the c, a, and [110] crystallographic directions in the tetragonal unit cell are determined via magnetization and heat capacity measurements. A complex series of phases and quantum phase transitions are discovered that depend strongly on both the magnitude and direction of the field. Our results show that \pcvo is an effective spin-1/2 antiferromagnetic Heisenberg-Ising chain with properties that are in general comparable to those of SrCo$_2$V$_2$O$_8$ and BaCo$_2$V$_2$O$_8$. One interesting departure from the results of these related compounds, is however, the discovery of a new field-induced phase for the field direction $H\|$[110] which has not been previously observed