PREPARATION AND PROPERTIES OF THERMOELECTRIC MATERIALS

Abstract

Molybdenum telluride, MoTe2, was prepared by chemical transport reaction. Pure Mo and Te are placed in a horizontal quartz tube at about 800 C. Deposition is accomplished at about 750 C wtih Br as the transport agent. The temperature gradient is important, small variations in temperature stopping the transport phenomenon and sometimes causing wide and thin crystals, 1 to 2 sq cm inAREA, TO GRO ON THE Mo; the crystals are probably Mo2Te3. The specific gravity of MoTe2 is 8.5; the crystals are soft and make black marks on paper. Standard X-ray analysis on single crystals of MoTe2 was performed with the rotating crystal method (Cu K-alpha radiation). The first lattice constant of the hexagonal system was expressed by the equation a equals 3.52 + or - 0.05 angstrom units. With the axis of rotation parallel to the c axis, c equals 14 + or - 0.2 angstroms. The following compounds are also being prepared: MoSe2, WSe2, and WTe2.

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1961
Accession Number
AD0257395

Tags

DTIC Thesaurus Topics

  • Absorbers (Materials)
  • Advanced Materials
  • Crystals
  • Engineered Materials
  • Equations
  • Isotherms
  • Materials
  • Molybdenum
  • Radiation
  • Rotation
  • Single Crystals
  • Specific Gravity
  • Standards
  • Temperature Gradients
  • Transport Ships
  • X Rays

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  • Thin Film Deposition Science.