Facilities

Materials Synthesis

Electrical Analysis

Thermal Analysis

Ab initio computations

Materials Synthesis

  • Vertigo – A vertical tube furnace for melting and long-duration heat treatments at temperatures up to 1100 °C.
  • Combo – A multipurpose box furnace operating up to 1100°C with protective atmosphere.
  • ThermoCeram – A Nabertherm high-temperature air furnace for sintering up to 1600 °C with an option for protective atmosphere.
  • Samson – A tube furnace combined with hydraulic press for hot-pressing of powders up to 700 ° C under protective atmosphere.
  • A two-stage EDWARDS-make vacuum system for evacuating and sealing of quartz ampoules at pressure <10-5 Torr.
  • A hydraulic press for cold uniaxial powder compaction up to 5,000 kgf.
  • A constant-force Buehler precision saw.

Thermal Analysis

A Netzsch LFA-457 apparatus for thermal conductivity measurements

The LFA-457 instrument is based on the “half-time” method, where a thermal pulse is generated on the sample’s surface on one side, and the thermal response is detected and temporally-resolved on the opposite side, thus yielding the temperature- dependent thermal diffusivity. The temperature- dependent heat capacity is also measured using standards. The product of these two magnitudes with the material’s density yields the temperature- dependent thermal conductivity.

Technical Details

Furnaces: -125°C to 500°C, RT to 1100°C
Measurement Atmosphere: He/Ar/Vacuum (<10-2 mbar)
Laser: Nd-YAG, up to 18 J, Minimum pulse duration 0.5 ms

Infra-Red Detectors: Mercury-Cadmium-Telluride/Indium-Antimonide
Data Acquisition: Control unit, Dedicated software
Thermal Conductivity Range:0.1 to 2000 Wm-1K-1, Accuracy ±3%
Thermal Diffusivity Range:0.01 to 1000 mm2/s, Accuracy ±2%

Electrical Analysis

A Netzsch SBA-458 NemesisTM system for simultaneous determination of Seebeck Coefficient (10 through 500 µV/K) and electrical conductivity (5 through 150,000 S/cm) at the range of room temperature through 1100 °C under protective atmosphere.

 

Hall Effect measurement system Ecopia HMS-5500 with 0.51 Tesla magnet kit (AMP55T) and 80-573 K temperature range:


Temperature range: 80-573 K 
Input current: 1 nA ~ 20mA
Resistivity: 10-4 ~ 107 Ω·cm
Mobility: 1~ 107 cm2/V·sec
Magnetic Flux Density: 0.51 T

Computational facilities

High-Performance Computing (HPC) cluster

WildCat is a  HPC cluster comprising 13 compute nodes with total capacity of 180 CPUs. The nodes are interconnected by a Mellanox high-speed infiniband switch (40 Gb/s) to speed-up parallel computing.

OS: CentOS Linux.

For small calculations we use a HouseCat stand alone computation node with 8 CPUs and 32 Gb shared memory.

OS: Ubuntu Linux.

MedeA software package

We utilize the MedeA 2.22 software package (Materials Design, Inc. 2015; Angel Fire, NM, USA) for ab-initio calculations. This package includes several components:

  • VASP 4.6 and 5.4 codes for plane-wave density functional theory (DFT) calculations;
  • MedeA graphical user interface;
  • InformaticA crystallographic database;
  • Phonon package for calculations of temperature-dependent thermodynamic properties;
  • Interface Builder for building simulation cells comprising interphase boundaries;
  • Electronics for calculation of electronic transport properties.
  • Medea LAMMPS for performing molecular dynamic calculations;