Materials Science Laboratory Facilities

Metal forging laboratory of the Throop Polytechnic Institute (which later became Caltech) circa 1898.

  • Transmission and Analytical Electron Microscopy. We have two transmission electron microscopes for materials research, both maintained under contract with FEI. The FEI Ultra-Twin F30 is a 300 keV instrument that is used for spectrometry and high resolution and HAADF imaging. It has an Oxford Instruments energy-dispersive x-ray spectrometer capable of x-ray mapping of Z>4, and a Gatan parallel-detection EELS spectrometer. A Philips heating holder and a Gatan liquid nitrogen cooling holder are available. Our Philips EM 420, a 120 keV instrument, is used for both instruction and research and is equipped with an AMT CCD camera. Specimen preparation facilities include equipment for electrochemical polishing, ion milling, ultramicrotomy, tripod polishing, plasma cleaning, plus the standard tools of metallography and optical microscopy.
  • Scanning Electron Microscopy. We are using a LEO field emission SEM that is maintained by the Geology and Planetary Sciences Division, and is available to us for analytical work. This unit has both energy dispersive and backscatter capability.
  • X-Ray Diffractometry. Our x-ray diffractometry facilities include a Philips PW3040-Pro diffractometer, equipped with a high counting efficiency, high dynamic range Xcellerator detector, in addition to two Inel CPS-120 powder diffractometer systems. Liquid nitrogen, hot stage and inert atmosphere capabilities are available for diffractometry work. A Siemens D-500 powder diffractometer is also available. For single crystal X-ray diffraction, the Haile group maintains a SYNTEX 4-circle diffractometer. Temperatures accessible with this instrument also range from 80K to 450K.
  • Inelastic Neutron Scattering. Prof. B. Fultz is the Principal Investigator for the DOE project to construct an inelastic chopper spectrometer at the Spallation Neutron Source (SNS) in Oak Ridge, TN. This instrument, ARCS, is designed to measure the energy and momenta spectra of neutrons that are scattered inelastically from a material, and ARCS will do so with an unprecedented combination of intensity and resolution. Inelastic neutron spectra can be used to measure the phonon density of states in a material, or spectra of magnetic and electronic excitations. ARCS begins operations in 2007.
  • Mössbauer Spectrometry. The Fultz group maintains two Mössbauer spectrometers which can be equipped with a transmission gamma-ray detector, backscatter conversion electron detector, or backscatter gamma-ray detector. A liquid helium cryostat and a furnace allow measurements over the temperature range 3 - 800 K. One of these units is being developed for Mössbauer diffraction experiments.
  • NMR spectrometers. The Caltech Solid-State NMR facility is located in the Sherman Fairchild Laboratory. The specific on-campus facilities and instruments that we have experience with are as follows; a) 200 MHz Bruker DSX-200 Avance (4.7 T) equipped with two Bruker 7 mm CP MAS probes, a Bruker Wide line probe, a Chemagnetics 7.5 mm CP MAS probe and a Bruker 10 mm liquid probe, b) a 300 MHz (7.0 T) Bruker AM 300 heavily modified to perform a variety of solid state NMR experiments and updated with the TECMAG and equipped with a Bruker 7 mm CP MAS probe, a Bruker 4 mm CP MAS probe, a 5 mm Bruker liquid probe and two 10 mm Bruker liquid probes, c) a 500 MHz Bruker DSX-500 Avance spectromter with UltraShield magnet (the first wide bore 11.7 T magnet installed in the world) and equipped with a Bruker 4 mm triple resonance CP MAS probe a Bruker 7 mm CPMAS probe for low frequency nuclei ($^{107}$Ag-$^{13}$C) and a 10 mm Bruker liquid probe.
  • Calorimetry. We have a Perkin Elmer DSC 7 differential scanning calorimeter, a Perkin Elmer DTA 7 differential thermal analyzer, Perkin Elmer DTA 1700 differential thermal analyzer, a Setaram HTC 1800K/DSC 2000K high temperature calorimeter, and a Perkin Elmer DSC 4 mounted in a liquid helium cryostat. We also have a Netzsch Pegasus DSC 404C calorimeter. The usable temperature range for calorimetry spans from 60 - 1800 K.
  • Thermogravimetric Analysis. For gravimetric analysis we operate a Perkin Elmer TGA 7 with a temperature capability of up to 1873 K.
  • Simultaneous Calorimetric and Gravimetric Analysis. For experiments in which sample variability dictates that calorimetric and gravimentric analyses be performed simultaneously, we have a Netzsch STA 449. This instrument offers much greater sensitivity in terms of both thermal events and weight change than the Perkin Elmer instruments. The temperature range accessible is 300K to 1873K. An evolved gas analyzer will soon be installed for elucidating material decomposition pathways.
  • Melting and Processing. Ingots can be melted with our Edmund Buehler (Tubingen) D-7400 Arc-Melting Apparatus. Its stainless steel chamber (high-vacuum capable with O-ring seals) is backfilled with argon gas. Our second system is an rf induction melting unit that levitation-melts an ingot on a water-cooled silver-boat under a purified argon atmosphere. Johnson's group has modified some of the induction furnaces for work with metallic glasses, such as for injection molding and for measurements of viscosity with controlled shear rates. We have an Edmund Buehler ultra-rapid quenching apparatus for splat-quenching in high vacuum or inert atmospheres. We also have a thermal evaporator with a cold-trapped diffusion pump available for making thin films, and a Perkin-Elmer UHV sputtering system. We have five Spex 8000 shaker ball mills and a second type of ball mill (Nisshin Corp. NEV-8A) with two environmentally controlled milling chambers for milling at temperatures from 100 K to 670 K. A Tetrahedron hot press is maintained by the Johnson group, and a rolling mill, swaging machine and many furnaces are also available.
  • High Temperature Furnaces. For work with ceramics and composites, the Haile and Ustundag groups operate a set of CM furnaces: (i) 1 horizontal tube furnace with atmosphere control option and a zirconia oxygen sensor (Tmax = 1973 K); (ii) 1 box furnace (Tmax = 1973 K); (iii) 2 horizontal tube furnaces with atmosphere control (Tmax = 1373 K); (iv) 1 box furnace with controlled atmosphere and mechanical testing option (Tmax = 2073 K).
  • Transport Measurements. The Haile group maintains two Hewlett-Packard impedance analyzers for measurements of ion transport characteristics over a wide range of frequencies (20 Hz to 1 GHz) under controlled atmospheres. Facilities for impedance spectroscopy with Solartron analyzers (1 mHz to 1 MHz) and PAR potentiostats are available for electrochemical measurements at JPL, as are facilities for Hall measurements, Seebeck coefficient measurements and thermal conductivity measurements.
  • Sievert's Apparatus. A volumetric Sieverts apparatus is available for measuring the thermodynamics of hydrogen sorption. This unit has been in constant operation since the beginning of 2004 and has been used primarily for measuring isotherms of physisorption materials. It is located in our labs on the Caltech campus. An identical Sieverts unit that we use routinely is located at JPL and is used primarily for measuring isotherms of metal-hydrogen systems over a temperature range of 298 - 600 K and pressures to 190 bar.
  • Magnetics Measurements. The Fultz group has built a computer-controlled facility for measuring the magnetostriction of materials at temperatures from 77 - 300 K, magnetic fields up to 6.5 kOe, and forces of 1000 Nt. Also available is a magnetometer for room temperature measurements of magnetizations of ferromagnetic materials.
  • Mechanical Properties Testing. We have a servo-hydraulic mechanical testing system (20 000 lb capacity) and a screw-driven Instron load frame (10 000 lb capacity). A high temperature furnace (Tmax = 2073 K) will be available for this equipment soon. Additionally, we have access tofacilities of the Aeronautics Option, which have capabilities for higher loads and permit dynamic tests. The Ustundag group is also installing a Tukon/Wilson microhardness tester with 10 kg maximum load capacity.
  • Thermal Expansion. The Johnson group maintains a Perkin Elmer thermomechanical analyzer model TMA 7, interfaced to a Perkin Elmer thermal analysis controller TAC 7/DX for measurements of linear thermal expansion. Fultz's group has constructed a system for differential thermal expansion measurements at temperatures from 4 - 300 K. The Ustundag group maintains a dilatometer for thermal expansion measurements and studies of sintering and phase transformations at temperatures up to 1873 K in controlled atmospheres.
  • Elastic Moduli. Prof. G. Ravichandran in Aeronautics and Solid Mechanics at Caltech is actively using a 30 MHz ultrasonic analyzer (Panametrics 5052 UA) for measuring elastic wave speeds in solid specimens. Transducers for both longitudinal and shear wave measurements are available, for either transmission or reflection geometry.
  • Computers. We maintain several computing resources. Amongst these are a 20 CPU Opteron 285 cluster, located and maintained within Caltech's Center for Advanced Computing Research. This cluster can be merged with 248 other CPUs for large MPI jobs. Graduate students and staff are provided individual networked personal computers.
  • Software. A large software environment has been developed on the workstations for running Monte Carlo simulations of phase transformations in crystalline materials, and for characterizing the lattice. Lattice dynamics codes are also maintained. Many analytical codes for phase transformations have also been developed in the point and pair approximations. The COSMOS finite element package is available. We also maintain GSAS and RIETAN packages for structural analysis with powder diffraction patterns.

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