Slit-collimated Laue diffraction using synchrotron radiation: an examination of the paraelectric-to-ferroelectric phase transformation in ammonium sulfate

Abstract The effects of 1-nm-thick CeOx capping on 7.5-nm-thick Y-doped HfO2 films on the ferroelectric characteristics are investigated. From the ferroelectric characteristics of the samples annealed at different temperatures from 450 to 600oC and annealing durations, the time (τ) required to stabilize the ferroelectric phase at each temperature was shortened by the capping. The identical activation energy (Ea) of 2.65 eV for ferroelectric stabilization without and with capping suggests the same kinetics for phase transformation. However, an increase in the remnant polarization (Pr) was obtained. Only a few Ce atoms diffused into the underlying HfO2 film even after 600oC annealing. Ferroelectric switching tests revealed an improvement in endurance from 107 to 1010 by the capping, presumably owing to the suppression of conductive filament formation. Therefore, CeOx capping is effective in promoting the ferroelectric phase in HfO2 with high switching endurance.

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A high-resolution Weissenberg camera for X-ray synchrotron radiation

Journal of Applied Crystallography ◽

10.1107/s0021889890004216 ◽

1990 ◽

Vol 23 (5) ◽

pp. 351-354

Author(s):

D. Hohlwein ◽

J. D. Axe

Keyword(s):

Phase Transformation ◽

High Resolution ◽

Synchrotron Radiation ◽

Reciprocal Space ◽

Experimental Results ◽

Germanium Crystal ◽

Synchrotron Source ◽

X Ray ◽

High Resolution Mapping ◽

Resolution Mapping

A photographic Weissenberg camera has been constructed which can be mounted on the 2θ arm of a four-circle diffractometer. At a distance of 0.5 m from the sample the 2θ resolution for a 100 μm crystal is 0.2 mrad (0.01°), allowing a high-resolution mapping of reciprocal space at a synchrotron source in an efficient way. As sample experimental results, a study is presented of the streak system around the 111 reflection of a perfect germanium crystal and the detection of a minute phase transformation in a single-powder grain of a high-Tc superconductor.

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A furnace for in situ synchrotron Laue diffraction and its application to studies of solid-state phase transformations

Journal of Applied Crystallography ◽

10.1107/s0021889890007257 ◽

1990 ◽

Vol 23 (6) ◽

pp. 545-549 ◽

Cited By ~ 8

Author(s):

H. L. Bhat ◽

S. M. Clark ◽

A. El Korashy ◽

K. J. Roberts

Keyword(s):

Experimental Data ◽

Thermal Stability ◽

Phase Transitions ◽

Solid State ◽

Synchrotron Radiation ◽

Structural Phase ◽

Structural Phase Transitions ◽

Laue Diffraction ◽

Thermal Stability Of

The design of a new microfurnace for use for Laue diffraction studies of solid-state transformations is described. The furnace operates in the temperature range 298–573 K with a thermal stability of about ± 0.1 K. The potential of the synchrotron-radiation Laue diffraction technique for studies of structural phase transitions is demonstrated. Experimental data on phase transitions in caesium periodate, potassium tetrachlorozincate and pentaerythritol are presented.

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