The effects of point defects and stoichiometry on structural phase transitions: Progress report, June 15, 1988--June 14, 1989

Technical Report · Sun Jan 01 04:00:00 EST 1989

DOI:https://doi.org/10.2172/6051462· OSTI ID:6051462

Toulouse, J.

In this report, we have discussed the effects of point defects on structural phase transitions in KMnF/sub 3/ and KTaO/sub 3/. KMnF/sub 3/ is a fluoperovskite that undergoes a cubic-to-tetragonal transition at 186.6/degree/K. Here, this transition has been studied in Li-doped crystals. KTaO/sub 3/ is an oxyperovskite that does not undergo a phase transition until it is doped with Nb or Li. The transition temperature T/sub c/ is then directly related to the defect or impurity concentration. These two systems are also representative of two separate types of phase transitions. This particular choice was made so as to be able to contrast the respective results obtained on the two systems and thus establish a general framework of reference.

• Research Organization: Lehigh Univ., Bethlehem, PA (USA). Dept. of Metallurgy and Materials Engineering
• DOE Contract Number: FG02-86ER45258
• OSTI ID: 6051462
• Report Number(s): DOE/ER/45258-T3; ON: DE89015758
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
ACOUSTIC TESTING
ALKALI METALS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DOCUMENT TYPES
DOPED MATERIALS
ELEMENTS
FLUORINE COMPOUNDS
HALOGEN COMPOUNDS
IMPURITIES
LITHIUM
MATERIALS
MATERIALS TESTING
METALS
NIOBIUM
NONDESTRUCTIVE TESTING
OXYGEN COMPOUNDS
PEROVSKITES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
POINT DEFECTS
POLARIZATION
PROGRESS REPORT
STOICHIOMETRY
TESTING
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
TRANSITION TEMPERATURE