Characterization of New Materials in A Four-Sample Thermoelectric Measurement System

2000 ◽  
Vol 626 ◽  
Author(s):  
Nishant A. Ghelani ◽  
Sim Y. Loo ◽  
Duck-Young Chung ◽  
Sandrine Sportouch ◽  
Stephan de Nardi ◽  
...  
Keyword(s):  
Measurement System ◽  
Thermoelectric Materials ◽  
Measurement Techniques ◽  
New Materials ◽  
Thermo Electric ◽  
New Synthesis ◽  
Wide Range ◽  
Materials Research ◽  
Computer Controlled

ABSTRACTSeveral new materials in the CsBi4Te6, A2Bi8Se13, (A = K, Rb, Cs), HoNiSb, Ba/Ge/B (B = In, Sn), and AgPbBiQ3 (Q = S, Se, Te) systems have shown promising characteristics for thermoelectric applications. New synthesis techniques are able to produce samples at much higher rates than previously possible. This has led to a persistent challenge in thermoelectric materials research of rapid and comprehensive characterization of samples. This paper presents a description of a new 4-sample transport measurement system and the related measurement techniques. Special features of the system include fully computer-controlled operation (implemented in LabView™) for simultaneous measurement of electrical conductivity, thermo-electric power, and thermal conductivity. This system has been successfully used to characterize several new thermoelectric materials (including some of the above-mentioned compounds) and reference materials exhibiting a wide range of thermal conductivities.

scholarly journals Applications with a brighter X-ray source and new detectors from Agilent

2014 ◽  
Vol 70 (a1) ◽  
pp. C1734-C1734
Author(s):  
Zoltan Gal ◽  
Tadeusz Skarzynski ◽  
Fraser White ◽  
Oliver Presly ◽  
Adrian Jones ◽  
...  
Keyword(s):  
Data Quality ◽  
Single Crystal ◽  
Measurement System ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Vacuum Technology ◽  
Intelligent Measurement ◽  
Wide Range

Agilent Technologies develop and supply X-ray systems for single-crystal diffraction research, including the SuperNova; a compact, highly reliable and very low maintenance instrument providing X-ray data of the highest quality; and the PX Scanner for testing and characterization of protein crystals in their original crystallization drops (in-situ). The SuperNova and PX Scanner are constantly improving, with recent enhancements including a new range of detectors using an Intelligent Measurement System. The Eos S2, Atlas S2 and Titan S2 detector range employs a smart sensitivity control of the electronic gain and is capable of instantaneously switching its binning modes thus providing unprecedented flexibility in tuning every exposure to provide the highest data quality for a wide range of experiments. We have also developed a completely new micro-focus X-ray source based on Gradient Vacuum technology, with novel filament and target designs. This novel source is an integral part of the new Agilent GV1000 X-ray diffractometer, which has been designed for applications that require even higher brightness of the X-ray beam.

Doping and Alloying Trends in New Thermoelectric Materials

2001 ◽  
Vol 691 ◽  
Author(s):  
Sim Loo ◽  
Sangeeta Lal ◽  
Theodora Kyratsi ◽  
Duck-Young Chung ◽  
Kuei-Fang Hsu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Sample Preparation ◽  
Measurement System ◽  
Thermoelectric Materials ◽  
Bulk Materials ◽  
Preparation Time ◽  
Short Sample ◽  
Hall Effect Measurements ◽  
Computer Controlled

ABSTRACTNew thermoelectric bulk materials such as CsBi4Te6 have shown superior properties to traditional materials, however, optimal performance requires continuing investigations of doping and alloying trends. A recently modified high throughput measurement system is presented for doping and alloying investigations in several new thermoelectric materials. The modification includes a four-probe configuration for more accurate measurements while maintaining a relatively short sample preparation time. The system is fully computer controlled and provides flexible contacts to accommodate various sample dimensions. Optimal compositions are then identified for further investigations in thermoelectric prototype modules. The most promising materials will be further characterized for electrical conductivity, thermoelectric power, thermal conductivity, and Hall effect measurements as a function of temperature.

Nanoscale Characterization of Materials

MRS Bulletin ◽  
1997 ◽  
Vol 22 (8) ◽  
pp. 17-21 ◽  
Author(s):  
Edward T. Yu ◽  
Stephen J. Pennycook
Keyword(s):  
Electron Microscopy ◽  
Materials Science ◽  
Experimental Techniques ◽  
Nanometer Scale ◽  
Comprehensive Treatment ◽  
Major Theme ◽  
Wide Range ◽  
Materials Research ◽  
Characterization Of Materials

One of the dominant trends in current research in materials science and related fields is the fabrication, characterization, and application of materials and device structures whose characteristic feature sizes are at or near the nanometer scale. Achieving an understanding of—and ultimately control over—the properties and behavior of a wide range of materials at the nanometer scale has therefore become a major theme in materials research. As our ability to synthesize materials and fabricate structures in this size regime improves, effective characterization of materials at the nanometer scale will continue to increase in importance.Central to this activity are the development and application of effective experimental techniques for performing characterization of structural, electronic, magnetic, optical, and other properties of materials with nanometer-scale spatial resolution. Two classes of experimental methods have proven to be particularly effective: scanning-probe techniques and electron microscopy. In this issue of MRS Bulletin, we have included eight articles that illustrate the elucidation of various aspects of nanometer-scale material properties using advanced scanningprobe or electron-microscopy techniques. Because the range of both experimental techniques and applications is extremely broad—and rapidly increasing—our intent is to provide several examples rather than a comprehensive treatment of this extremely active and rapidly growing field of research.

Measurement Techniques for Thermoelectric Materials and Modules

2003 ◽  
Vol 793 ◽  
Author(s):  
Tim Hogan ◽  
Sim Loo ◽  
Fu Guo ◽  
Jarrod Short
Keyword(s):  
Thermoelectric Materials ◽  
Material Properties ◽  
Coefficient Of Thermal Expansion ◽  
Measurement Techniques ◽  
Theoretical Models ◽  
Large Temperature ◽  
New Materials ◽  
Accurate Analysis ◽  
Module Design ◽  
Insight Into

ABSTRACTThermoelectrics is a multidiscipline area of study, rich in condensed matter physics, chemistry, engineering, and material science. The figure of merit used for evaluating individual materials consists of three interdependent material properties. The measurement of these properties should be taken on the same sample for all three measurements, preferably simultaneously. Each of these measurements requires close attention to potential sources of losses for accurate analysis of the materials and testing of theoretical models. For example, relatively simple scanning measurement techniques can be used to gain insight into accurate geometry measurements and influences of contact dimensions. In addition, the field of thermoelectrics spans a wide temperature range, from cryogenic temperatures to > 1000 °C. This requires systems capable of large temperature variations, and/or multiple measurement systems for various ranges of interest. Additional measurements, such as Hall effect, help to gain further insight into the material properties and their optimization. The number and importance of measurements is further extended as the development of devices from these new materials is initiated, where studies of contact resistance and overall device performance must be evaluated. For mechanical robustness of fabricated modules, properties such as the coefficient of thermal expansion, and grain size for the new materials are of interest. Models for device behavior are useful in evaluating the measured results and further extracting material and device properties. In this paper, we review measurements used in evaluating bulk thermoelectric materials some of the information that can be extracted from these measurements, along with a model that can be used in conjunction with these measurements for module design.

Characterization of Thermoelectric Power Generation Modules Made from New Materials

2005 ◽  
Vol 886 ◽  
Author(s):  
Jarrod L. Short ◽  
Jonathan D'Angelo ◽  
Adam D. Downey ◽  
Michael A. Pajor ◽  
Ed Timm ◽  
...  
Keyword(s):  
Power Generation ◽  
Thermoelectric Power ◽  
Measurement System ◽  
Figure Of Merit ◽  
Temperature Gradients ◽  
Michigan State University ◽  
State University ◽  
New Materials ◽  
Made In

ABSTRACTLead-Antimony-Silver-Tellurium (L-A-S-T) materials, synthesized at Michigan State University, show promising thermoelectric properties at high temperatures for use in power generation applications. Recent scaled-up quantities of L-A-S-T show a ZT=1.4 at 700 K approaching the figure of merit for samples made in small quantities. These materials are of great interest for power generation applications with hot side temperatures in the range of 600-800 K. Developing these materials into working devices requires minimization of the thermal and electrical parasitic contact resistances, so various fabrication methods are under investigation. To examine each method, a new measurement system has been developed to characterize these devices under various load and temperature gradients. An introduction to the system will be presented, as well as results for devices made of the L-A-S-T materials.

Magnetic Characterization of CoFe2O4 Nanoparticles

2003 ◽  
Vol 789 ◽  
Author(s):  
G. Lawes ◽  
B. Naughton ◽  
D. R. Clark ◽  
A. P. Ramirez ◽  
R. Seshadri
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Ac Susceptibility ◽  
Measurement Techniques ◽  
Anomalous Behavior ◽  
Magnetic Characteristics ◽  
Magnetic Characterization ◽  
Wide Range ◽  
Co Precipitation

We have synthesized CoFe2O4 nanoparticles with length scales ranging from 3.5 nm to 14.2 nm. We have characterized the magnetic properties of these samples using both DC and AC magnetization, and find some slightly anomalous behavior in two of the samples. We tentatively attribute these features to interactions between the magnetic nanoparticles.There is a great deal of interest in understanding the physical basis for the magnetic properties of nanoparticles in order to facilitate their incorporation into a wide range of commercial applications. By studying the magnetic characteristics of CoFe2O4 nanoparticles using bulk measurement techniques, we are able to probe the properties of both the individual nanoparticles and interactions in these systems. In this report, we discuss our magnetic characterization of a series of CoFe2O4 nanoparticles grown using an aqueous co-precipitation technique. In addition to DC magnetization at fixed fields and temperatures, we also investigated the magnetic properties using AC susceptibility measurements. The long term goal of this research is to understand interparticle interactions in magnetic nanoparticles.

Experimental Characterization of Contact Hysteresis at High Temperatures

2006 ◽  
Author(s):  
Sergio Filippi ◽  
Esequiel B. Rodrigues ◽  
Muzio M. Gola
Keyword(s):  
Friction Coefficient ◽  
Experimental Determination ◽  
Measurement System ◽  
Experimental Characterization ◽  
Test Rig ◽  
Tangential Load ◽  
Wide Range ◽  
Induction System

The current paper presents a measurement system for the experimental determination of contact hysteresis cycles at temperatures up to 800° C. A test rig was designed to conduct experiments in a wide range of temperatures, with different combinations of normal and tangential load, frequencies and contacting materials. An induction system supplies the heat for measurements of hysteresis cycles at the required temperatures. Measurements show the dependence of the friction coefficient on temperature.

Modeling the Thermoelectric Properties of Nanocomposites

2008 ◽  
Author(s):  
Austin Minnich ◽  
Gang Chen
Keyword(s):  
Grain Boundary ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Boundary Scattering ◽  
Full Characterization ◽  
Scattering Rate ◽  
Relaxation Time Approximation ◽  
Grain Boundary Scattering ◽  
Wide Range

Modeling the thermoelectric properties of nanocomposites is difficult due to the complex grain boundary scattering processes which scatter both electrons and phonons. In this work we describe a code we developed which numerically calculates the electrical and thermal properties of bulk and nanocomposite thermoelectric materials using the Boltzmann equation under the relaxation time approximation. The code is capable of calculating all the relevant thermoelectric properties over a wide range of temperatures, doping concentrations, and compositions, allowing for a full characterization of the material. We model nanocomposites by incorporating a grain boundary scattering rate based on a simple model we developed and models in the literature. The code and grain boundary scattering models are validated on bulk data and data from nano-SiGe, and are then applied to other candidate thermoelectric materials to see if they would be good candidates for nanocomposites. The analysis shows that GaAs might be promising as a nanocomposite thermoelectric material.

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