Fragile phase stability in (1-x)Pb(Mg{sub 1/3}Nb{sub 2/3}O{sub 3})-xPbTiO{sub 3} crystals: A comparison of [001] and [110] field-cooled phase diagrams

Journal Article · Mon May 01 00:00:00 EDT 2006 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.73.1· OSTI ID:20788171

Cao, Hu; Li, Jiefang; Viehland, D; Xu, Guangyong ^[1]

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1. Department of Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)

Phase diagrams of [001] and [110] field-cooled (FC) (1-x)Pb(Mg{sub 1/3}Nb{sub 2/3}O{sub 3})-xPbTiO{sub 3} or PMN-xPT (0.15{<=}x{<=}0.38) crystals have been constructed, based on high-resolution x-ray diffraction data. Comparisons reveal several interesting findings. First, a region of abnormal thermal expansion (c{ne}a) above the dielectric maximum was found, whose stability range extended to higher temperatures on application of electric field (E). Second, the rhombohedral (R) phase of the zero-field-cooled (ZFC) state was replaced by monoclinic M{sub A} in the [001] FC diagram, but with monoclinic M{sub B} in the [110] FC. Third, the monoclinic M{sub C} phase in the ZFC and [001] FC diagram was replaced by an orthorhombic (O) phase in the [110] FC diagram. Finally, in the [001] FC diagram, the phase boundary between tetragonal (T) and M{sub A} phases was extended to lower PT content (x=0.25); whereas in the [110] FC diagram, this extended region was entirely replaced by the O phase. These results clearly demonstrate that the phase stability of PMN-xPT crystals is quite fragile--depending not only on modest changes in E, but also on the direction along which E is applied.

• OSTI ID: 20788171
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 73, Issue 18; Other Information: DOI: 10.1103/PhysRevB.73.184110; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPARATIVE EVALUATIONS
CONCENTRATION RATIO
CRYSTALS
ELECTRIC FIELDS
FERROELECTRIC MATERIALS
LEAD COMPOUNDS
MAGNESIUM COMPOUNDS
MONOCLINIC LATTICES
NIOBIUM COMPOUNDS
ORTHORHOMBIC LATTICES
PHASE DIAGRAMS
PHASE STABILITY
PHASE TRANSFORMATIONS
THERMAL EXPANSION
TITANATES
X-RAY DIFFRACTION