Thermal properties and radiation damage in NaNH[sub 4]XO[sub 4][center dot]2H[sub 2]O single crystals (XO[sub 4] = SO[sub 4], SeO[sub 4])

Journal Article · Wed Jul 01 00:00:00 EDT 1992 · International Journal of Thermophysics; (United States)

DOI:https://doi.org/10.1007/BF00501952· OSTI ID:5985151

Hilczer, B; Szczepanska, L ^[1]; Piskunowicz, P ^[2]; Darwish, H G ^[3]

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1. Institute of Molecular Physics, Poznan (Poland)
2. A. Mickiewicz Univ., Poznan (Poland)
3. Alexandria Univ., Alexandra (Egypt)

Differential thermal analysis (DTA) studies of NaNH[sub 4]SO[sub 4][center dot]2H[sub 2]O, NaND[sub 4]SO[sub 4][center dot]2H[sub 2]O, and NANH[sub 4]SeO[sub 4][center dot]2H[sub 2]O single crystals were performed in the temperature range of the ferroelectric-paraelectric phase transition and of the dehydration process. The first-order phase transition at the Curie point was confirmed for NaNH[sub 4]SO[sub 4][center dot]2H[sub 2]O, whereas the transition in the isomorphous NaNH[sub 4]SeO[sub 4][center dot]2H[sub 2]O at the Curie temperature was found to be similar to a continuous (second order) with considerable higher transition enthalpy. Dehydration process of the crystals studied was found to proceed in two stages, with maximum dehydration rates at [approximately]355 and [approximately]400 K. A linear decrease in thermal energy related to the long-range ordering in NaNH[sub 4]SO[sub 4][center dot]2H[sub 2]O crystals was observed with the dose of [gamma]-cobalt-60 irradiation and discussed with respect to the radiation induced decrease in spontaneous polarization. 17 refs., 5 figs., 2 tabs.

• OSTI ID: 5985151
• Journal Information: International Journal of Thermophysics; (United States), Vol. 13:4; ISSN 0195-928X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMMONIUM SULFATES
IRRADIATION
COBALT 60
RADIATION EFFECTS
MONOCRYSTALS
CRYSTAL-PHASE TRANSFORMATIONS
DIFFERENTIAL THERMAL ANALYSIS
SODIUM SULFATES
CURIE POINT
DEHYDRATION
ENTHALPY
FERROELECTRIC MATERIALS
POLARIZATION
ALKALI METAL COMPOUNDS
AMMONIUM COMPOUNDS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
COBALT ISOTOPES
CRYSTALS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
RADIOISOTOPES
SODIUM COMPOUNDS
SULFATES
SULFUR COMPOUNDS
THERMAL ANALYSIS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
YEARS LIVING RADIOISOT
360605* - Materials- Radiation Effects
360602 - Other Materials- Structure & Phase Studies