In this paper, we report our method of fabricating nanoscale multilayered Bi2Te3/Sb2Te3 thin film-based integrated thermoelectric devices, and detail the voltage and power produced by the device. The multilayered Bi2Te3/Sb2Te3 thin film was grown via e-beam evaporation; it had 20 alternating Bi2Te3- and Sb2Te3-layers, each layer being 1.5 nm thick. We characterized the film using high-resolution transmission electron microscopy (HRTEM), revealing its excellent cross-sectional structure without any obvious interface defects. The Bi2Te3/Sb2Te3 multilayer films were investigated by synchrotron X-ray scattering. An integrated device including 128 x 256 thermoelectric elements was fabricated from the multilayered film. An open-circuit voltage of 51 mV and a maximum power of 21 nW were produced from this 30 nm-thick Bi2Te3/Sb2Te3 multilayer TE device, and a temperature gradient of about 0.5 K/mu m was established across the multilayered film. We found that the nanoscale multilayer structure significantly affects the voltage and power produced. The fabrication of the integrated thermoelectric devices is compatible to that of generating standard integrated circuits (ICs), and is scalable for producing higher voltage and power, or achieving solid-state cooling for on-chip applications.

In this paper, we report our method of fabricating nanoscale multilayered Bi 2 Te 3 /Sb 2 Te 3 thin film-based integrated thermoelectric devices, and detail the voltage and power produced by the device. The multilayered Bi 2 Te 3 /Sb 2 Te 3 thin film was grown via e-beam evaporation; it had 20 alternating Bi 2 Te 3 - and Sb 2 Te 3 -layers, each layer being 1.5 nm thick. We characterized the film using high-resolution transmission electron microscopy (HRTEM), revealing its excellent cross-sectional structure without any obvious interface defects. The Bi 2 Te 3 /Sb 2 Te 3 multilayer films were investigated by synchrotron X-ray scattering. An integrated device including 128 × 256 thermoelectric elements was fabricated from the multilayered film. An open-circuit voltage of 51 mV and a maximum power of 21 nW were produced from this 30 nm-thick Bi 2 Te 3 /Sb 2 Te 3 multilayer TE device, and a temperature gradient of about 0.5 K/μm was established across the multilayered film. We found that the nanoscale multilayer structure significantly affects the voltage and power produced. The fabrication of the integrated thermoelectric devices is compatible to that of generating standard integrated circuits (ICs), and is scalable for producing higher voltage and power, or achieving solid-state cooling for on-chip applications. Display Omitted • Integrated thermoelectric device including 128 × 256 TE elements was fabricated with the nanoscale multilayered Bi 2 Te 3 /Sb 2 Te 3 thin film. • X-ray reflection was used to analyze the interface variation of the nanoscale multilayer structure before and after temperature annealing. • Nanoscale multilayer structure can significantly enhance thermoelectric response, and increase the voltage and power produced.

Characterization of Atomic and Molecular Structure: Diffraction and Scattering Synchrotron X-Ray Scattering: Probing Structure for the Structure-Function Relationship, Elaine DiMasi In situ X-ray scattering from molecular templates and nucleating minerals at organic-water interfaces, Benjamin D. Stripe and Pulak Dutta Electron Backscatter Diffraction for Biomineralization, Maggie Cusack and Peter Chung Characterization of Atomic and Molecular Structure: Spectroscopy and Spectro-Microscopy Infrared Spectroscopy and Imaging, Adele L. Boskey, PhD Raman Spectroscopy in Biomineralization, Karen Esmonde-White and Francis Esmonde-White Chemical Mapping with X-Ray Absorption Spectroscopy, Yannicke Dauphin and Murielle Salome Local Structure Development Characterization of Biominerals Using X-Ray Absorption Spectroscopy, Yael Politi and Ivo Zizak Soft x-Ray Scanning Transmission Spectro-Microscopy, Julie Cosmidis and Karim Benzerara Photoemission Spectromicroscopy for the Biomineralogist, Pupa U. P. A. Gilbert Solid-State NMR Spectroscopy: A Tool for Molecular-Level Structure Analysis and Dynamics, Melinda J. Duer The Realities of Disordered or Unfolded Proteins: Relevance to Biomineralization, John Spencer Evans Imaging Morphology and Interfaces Exploring Dynamics at the Biomolecule-Crystal Interface Using Real-Time In Situ Atomic Force Microscopy, S. Roger Qiu In situ Atomic Force Microscopy as a tool for investigating assembly of protein matrices, Sungwook Chung and James J. De Yoreo Transmission Electron Microscopy in Biomineralization Research: Advances and Challenges, Elia Beniash, Archan Dey, and Nico A. J. M. Sommerdijk X-Ray Computed Tomography, Xianghui Xiao and Stuart R. Stock SIMS Method and Example of Applications in Coral Biomineralization, Claire Rollion-Bard and Dominique Blamart Properties of the Composite: Energetics and Forces in Assembly Molecular Simulation of Biomineral Nucleation And Crystal Growth: Modern Computational Challenges and Approaches, Yang Yang, Zhijun Xu, Qiang Cui, and Nita Sahai Application of Enhanced Sampling Approaches to the Early Stages of Mineralization, Adam F. Wallace and James J. De Yoreo Direct Measurement of Interaction Forces and Energies with Proximal Probes, Raymond W. Friddle Properties of the Composite: Materials Approaches to Tissues and Whole Organs Measuring Forces between Structural Elements in Composites: From Macromolecules to Bone, Philipp J. Thurner and Orestis L. Katsamenis Mechanical and Interface Properties of Biominerals: Atomistic to Coarse Grained Modeling, Arun K. Nair, Flavia Libonati, Zhao Qin, Leon S. Dimas, and Markus J. Buehler Whole Organ Deformation Analysis by Digital Optical Metrology Methods, Paul Zaslansky and Ron Shahar Illustrating Biodiversity: The Power of an Image, James C. Weaver and Elaine DiMasi

We present the first resonant x-ray reflectivity measurements from a liquid surface. The surface structure of the liquid Hg-Au alloy system just beyond the solubility limit of 0.14at% Au in Hg had previously been shown to exhibit a unique surface phase characterized by a low-density surface region with a complicated temperature dependence. In this paper we present reflectivity measurements near the Au LIII edge, for 0.2at% Au in Hg at room temperature. The data are consistent with a concentration of Au in the surface region that can be no larger than about 30at%. These results rule out previous suggestions that pure Au layers segregate at the alloy surface.

Mineral nucleation at a Langmuir film interface has been studied by synchrotron x-ray scattering. Diluted calcium bicarbonate solutions were used as subphases for arachidic and stearic acid monolayers, compressed in a Langmuir trough. Self-assembly of the monolayer template is observed directly, and subsequent crystal growth monitoredin-situ.

In this article, the authors report on the development of solid-state integrated cooling devices using Bi2Te3/Sb2Te3 and Bi2Te3/Bi2Te2Se thermoelectric thin films fabricated using sputtering deposition. The multilayer thin films have a periodic structure consisting of alternating Bi2Te3 and Sb2Te3 layers or Bi2Te3 and Bi2Te2Se layers, where each layer is about 10 nm thick. The deposited Bi2Te3/Sb2Te3 multilayer thin film has a p-type conductivity and the deposited Bi2Te3/Bi2Te2Se multilayer thin film has an n-type conductivity. The multilayer structure of films and the interface of layers were analyzed by x-ray diffraction and reflectivity. Bi2Te3/Sb2Te3 and Bi2Te3/Bi2Te2Se multilayer thin film-based integrated cooling devices were fabricated using standard integrated circuit fabrication process. The temperature difference was measured from the fabricated cooling devices. The devices could be good candidates for the application of high-efficiency solid-state microcooling.

Small angle X-ray diffraction from the uniaxial nematic phase of certain bent-core liquid crystals is shown to be consistent with the presence of molecular clusters possessing short-range tilted smectic (smectic-C) order. Persistence of these clusters throughout the nematic phase, and even into the isotropic state, likely accounts for the unusual macroscopic behavior previously reported in bent-core nematics, including an anomalously large flexoelectric effect (∼ 1000 times that of conventional calamitic nematics), very large orientational and flow viscosities (∼ 10–100 and ∼ 100–1000 times, respectively, typical values for calamitics), and an extraordinary flow birefringence observed in the isotropic state.

X-ray absorption fine structure spectroscopy has been used to study the chemical and structural properties of self-forming diffusion barrier layers from Cu-8 at. % Mn alloy films on porous low-k and thermally grown SiO2 dielectrics. For the porous low-k/Cu(Mn) system, we provide evidence that the interface is composed of MnSiO3 and MnO with near complete Mn segregation from the alloy film; however, we find that the self-forming process does not go to full completion on thermally grown SiO2 substrates.

Liquid crystals are intriguing electrically responsive soft matter systems. We report previously unexplored field-induced changes in the structures of some frustrated liquid crystal phases and describe them theoretically. Specifically, we have discovered using resonant x-ray scattering that the four-layer intermediate smectic phase can undergo either a transition to the ferrielectric (three-layer) phase or to the ferroelectric phase, depending on temperature. Our studies of intermediate phases using electric fields offer a way to test theories that describe ferroelectricity in self-assembling fluids.

Brookhaven National Laboratory • National Synchrotron Light Source • P.O. Box 5000, Upton, NY 11973 • http://www.nsls.bnl.gov/ FUNDING Engineering and Physical Sciences Research Council; National Science Foundation; Petroleum Research Fund, administered by the American Chemistry Society; Portuguese Foundation for Science and Technology; The University of Manchester; University of Minnesota; U.S. Department of Energy PUBLICATIONs S. Jaradat, et al., “Unexpected FieldInduced Phase Transitions Between Ferrielectric and Antiferroelectric Liquid Crystal Structures,” Phys. Rev. E, 77: 010701(2008).

A binary mixture of an antiferroelectric liquid-crystal material containing a selenium atom and a highly chiral dopant is investigated using resonant X-ray scattering. This mixture exhibits a remarkably wide four-layer intermediate smectic phase, the structure of which is investigated over a temperature range of 16K. Analysis of the resonant X-ray scattering data allows accurate measurement of both the helicoidal pitch and the distortion angle as a function of temperature. The former decreases rapidly as the SmC * phase is approached, whilst the latter remains constant over the temperature range studied at 8°±3° . We also observe that the senses of the helicoidal pitch and the unit cell of the repeating four-layer structure are opposite in this mixture and that there is no pitch inversion over the temperature range studied.

Biological mineralization of tissues in living organisms relies on proteins that preferentially nucleate minerals and control their growth. This process is often referred to as “templating,” but this term has become generic, denoting various proposed mineral–organic interactions including both chemical and structural affinities. Here, we present an approach using self-assembled networks of elastin and fibronectin fibers, similar to the extracellular matrix. When induced onto negatively charged sulfonated polystyrene surfaces, these proteins form fiber networks of ≈10-μm spacing, leaving open regions of disorganized protein between them. We introduce an atomic force microscopy-based technique to measure the elastic modulus of both structured and disorganized protein before and during calcium carbonate mineralization. Mineral-induced thickening and stiffening of the protein fibers during early stages of mineralization is clearly demonstrated, well before discrete mineral crystals are large enough to image by atomic force microscopy. Calcium carbonate stiffens the protein fibers selectively without affecting the regions between them, emphasizing interactions between the mineral and the organized protein fibers. Late-stage observations by optical microscopy and secondary ion mass spectroscopy reveal that Ca is concentrated along the protein fibers and that crystals form preferentially on the fiber crossings. We demonstrate that organized versus unstructured proteins can be assembled mere nanometers apart and probed in identical environments, where mineralization is proved to require the structural organization imposed by fibrillogenesis of the extracellular matrix.

The recent years have witnessed an extraordinary development in the study of electronic orderings in strongly correlated systems, a subject that was initiated back in the mid fifties. This development is, to a large extent, due to the advent of high flux, high brilliance 3 generation synchrotron light sources (ESRF, APS, Spring-8 and many others actually being built) and the possibility of directly measuring the electronic orderings themselves and not the lattice distortions induced by them. Charge orderings, orbital orderings and particularly odd magnetic orderings have been thus revealed for the first time and studied in resonant X-ray scattering (RXS) experiments. By virtue of its wavelength tunability these X-ray sources can easily operate at the absorption edges of a given atom and probe unoccupied final states of the atom. As we are dealing with electronic orderings, both crystallography and resonant atom spectroscopy are concerned and the goal is to optimize both simultaneously: to be able to collect data with the resolution of the spectroscopy techniques and in wide variety of Bragg reflections to finally be capable to render all data consistent within a model. Thereby the experimental protocol is of tantamount importance and has to be worked out prior to any such undertaking. Note that the accuracy needed here is orders of magnitude greater than that required by, for instance, MAD techniques. The underlying crystallography that one may end up doing in these electronic orderings is thus the twilight zone of both well known disciplines. In this presentation we will discuss several examples where charge ordering is at the core of relevant features of the compounds: (a) NaV2O5 [1,2] and the onset of a spin-singlet quantum ground state, (b) NdNiO3 [3] where charge disproportionation at the metal sites or a ligand hole ordering bond center ordering, triggers the magnetic ordering and further stabilizes the magnetic structure and finally (c) Fe3O4 [4] where the observation of charge ordering by RXS requires a very special care of the experimental conditions. Recipes and insights on the way RXS experiments should be carried out and further analyzed will be given as well.

Calcite crystals were nucleated from MgCl2/CaCl2 solutions onto functionalized self-assembled monolayers adsorbed onto E-beam evaporated Au films. Synchrotron X-ray scattering studies of the crystals reveal new information about preferred orientation and Mg incorporation. The Au [111] axis is distributed within 2.6 degrees of the film surface normal, but the oriented crystals may be tilted up to 6 degrees away from this axis. For low Mg2+ content, SO3--functionalized films nucleated primardy near the (106) calcite face, odd-chain-length carboxylic acid terminated alkanethiol films nucleated near the (012) face, and even-chain-length carboxylic acid terminated alkanethiol films nucleated near the (113) face. [Mg2+]/[Ca2+] concentration ratios (n) of 2 and greater defeated this preferred orientation and created a powder texture. Diffraction patterns within the layer plane from the coarse calcite powders indicated a shift to higher 2 theta accompanied by peak broadening with increasing n. For 0.5 < n < 3.5, a double set of calcite peaks is observed, showing that two distinct Mg calcite phases form: one of comparatively lower Mg content, derived from the templated crystals, and a Mg-rich phase derived from amorphous precursor particles. According to the refinement of lattice parameters, Mg incorporation of up to 18 mol % occurs for n = 4, independent of film functionality. We discuss the differences between the differently functionalized monolayers and also introduce the hypothesis that two separate routes to Mg calcite formation occur in this system.

The three-dimensional structure of the calcite (104)–water interface has been determined with surface X-ray scattering. Nine crystal truncation rods (including specular and non-specular rods) were measured providing both vertical and lateral sensitivity to the interfacial structure. The results reveal that calcite is nearly ideally terminated with a single surface hydration layer that includes two inequivalent water molecules having distinct heights of 2.3±0.1 and 3.5±0.2Å, each with a well-defined lateral registry with respect to the calcite surface. No additional layering of water is observed beyond this surface hydration layer. Small displacements in the outer two calcium carbonate layers were also observed. These results are compared with previous experimental and computational results.

We have studied colloidal suspensions of clay particles in aqueous salt solutions. These suspensions make excellent model systems for the study of interactions between plate-shaped particles, due to the inherent possibility of tuning their electrostatic repulsion with the concentration of the salt. Various gel and sol structures are possible, including nematic liquid crystalline order, although only qualitative identification of the latter in clay colloids has been available so far. Here, we briefly review our earlier synchrotron X-ray diffraction from gravity dispersed solutions of Na fluorohectorite, a synthetic swelling clay, over a large NaCl concentration range. Our use of liquid X-ray scattering techniques allowed us to identify regions in which particles reorient from horizontal to vertical alignments in strata coexisting at different heights within the sample. We thus identified two distinct gel regions characterized by differences in orientational anisotropy and domain size. In addition, we for the first time, present visual observations of birefringence in these systems; these new observations support the interpretation of our X-ray experiments, and thus our new results provide further evidence for nematic order.