Matches in SemOpenAlex for { <https://semopenalex.org/work/W2023786688> ?p ?o ?g. }
Showing items 1 to 74 of
74
with 100 items per page.
- W2023786688 abstract "The heat capacity C p of ammonium chloride, ammonium bromide and the mixed crystal NH 4 Br 0.55 Cl 0.45 has been analysed, for temperatures in the range 0-500 K, on the assumption that can be expressed as the sum of the terms ( C p — C v ), C (lat.), C (lib.), C (int.) and C (extra); C (lat.), C (lib.) and C (int.) are respectively, the contributions from the lattice vibrations (phonons), and the librations (torsional oscillations) and internal vibrations of the ammonium ions. C (extra) is the contribution from order-disorder changes or any other ‘abnormal’ sources. The analysis requires a knowledge of certain thermodynamic and spectroscopic properties of the crystals, and current information on these has been surveyed. The ‘normal ’ or ‘baseline’ heat capacity C´ p for the three solids has been estimated; C´ p is the molar heat capacity to be expected from the progressive excitation of the lattice vibrations, torsional oscillations and internal vibration of the cations, and from the expansion of the lattice. By comparing C´ p and the observed heat capacity C p , C (extra) has been evaluated, making it possible to examine the development with rising temperature of the configurational or otherwise ‘extra’ entropy. The main results emerging from this are the following, ( a ) For all three solids, the entropy gain at the λ-transition (or at the two lower transitions, taken together, in ammonium bromide) is not about R ln 2, as has often been stated, but is roughly 50 % larger. The excess over R ln 2 is to be attributed to changes in the phonon spectrum and to a reduction in the frequency of the torsional oscillations of the ammonium ions, ( b ) The heat capacity of the β-phase of all three solids is abnormally large. Possible reasons for this are briefly discussed, but a definitive explanation is lacking. ( c ) The overall entropy gain for all three solids when the high-temperature face-centred a-phase has been formed is considerably greater than R In 6, the configurational contribution to be expected from the structural evidence that each ammonium ion in this phase has access to six distinguishable orientations. The balance is believed to be due to enhanced freedom of torsional movement of the ammonium ions, which must be a complex motion. However, from its observable thermodynamic consequences, this motion is still far from true free rotation." @default.
- W2023786688 created "2016-06-24" @default.
- W2023786688 creator A5058831285 @default.
- W2023786688 creator A5062170893 @default.
- W2023786688 creator A5081068931 @default.
- W2023786688 date "1980-10-31" @default.
- W2023786688 modified "2023-09-27" @default.
- W2023786688 title "The thermodynamics of mixed crystals of ammonium chloride and ammonium bromide. II. An analysis of the heat capacity of ammonium chloride, ammonium bromide, and an approximately equimolar solid solution of these salts" @default.
- W2023786688 cites W2002102398 @default.
- W2023786688 cites W2039769203 @default.
- W2023786688 cites W2125607694 @default.
- W2023786688 doi "https://doi.org/10.1098/rspa.1980.0126" @default.
- W2023786688 hasPublicationYear "1980" @default.
- W2023786688 type Work @default.
- W2023786688 sameAs 2023786688 @default.
- W2023786688 citedByCount "7" @default.
- W2023786688 countsByYear W20237866882017 @default.
- W2023786688 crossrefType "journal-article" @default.
- W2023786688 hasAuthorship W2023786688A5058831285 @default.
- W2023786688 hasAuthorship W2023786688A5062170893 @default.
- W2023786688 hasAuthorship W2023786688A5081068931 @default.
- W2023786688 hasConcept C106301342 @default.
- W2023786688 hasConcept C121332964 @default.
- W2023786688 hasConcept C147789679 @default.
- W2023786688 hasConcept C178790620 @default.
- W2023786688 hasConcept C179104552 @default.
- W2023786688 hasConcept C185592680 @default.
- W2023786688 hasConcept C2776300020 @default.
- W2023786688 hasConcept C2779465129 @default.
- W2023786688 hasConcept C2779660836 @default.
- W2023786688 hasConcept C2779870022 @default.
- W2023786688 hasConcept C58226133 @default.
- W2023786688 hasConcept C60205243 @default.
- W2023786688 hasConcept C97355855 @default.
- W2023786688 hasConceptScore W2023786688C106301342 @default.
- W2023786688 hasConceptScore W2023786688C121332964 @default.
- W2023786688 hasConceptScore W2023786688C147789679 @default.
- W2023786688 hasConceptScore W2023786688C178790620 @default.
- W2023786688 hasConceptScore W2023786688C179104552 @default.
- W2023786688 hasConceptScore W2023786688C185592680 @default.
- W2023786688 hasConceptScore W2023786688C2776300020 @default.
- W2023786688 hasConceptScore W2023786688C2779465129 @default.
- W2023786688 hasConceptScore W2023786688C2779660836 @default.
- W2023786688 hasConceptScore W2023786688C2779870022 @default.
- W2023786688 hasConceptScore W2023786688C58226133 @default.
- W2023786688 hasConceptScore W2023786688C60205243 @default.
- W2023786688 hasConceptScore W2023786688C97355855 @default.
- W2023786688 hasLocation W20237866881 @default.
- W2023786688 hasOpenAccess W2023786688 @default.
- W2023786688 hasPrimaryLocation W20237866881 @default.
- W2023786688 hasRelatedWork W1613611120 @default.
- W2023786688 hasRelatedWork W1966788090 @default.
- W2023786688 hasRelatedWork W1970033462 @default.
- W2023786688 hasRelatedWork W1973323915 @default.
- W2023786688 hasRelatedWork W1974690524 @default.
- W2023786688 hasRelatedWork W1978502583 @default.
- W2023786688 hasRelatedWork W2002892600 @default.
- W2023786688 hasRelatedWork W2019372996 @default.
- W2023786688 hasRelatedWork W2023582267 @default.
- W2023786688 hasRelatedWork W2028584227 @default.
- W2023786688 hasRelatedWork W2054186400 @default.
- W2023786688 hasRelatedWork W2055190537 @default.
- W2023786688 hasRelatedWork W2071720066 @default.
- W2023786688 hasRelatedWork W2073486135 @default.
- W2023786688 hasRelatedWork W2083807684 @default.
- W2023786688 hasRelatedWork W2093527135 @default.
- W2023786688 hasRelatedWork W2102122016 @default.
- W2023786688 hasRelatedWork W2128679051 @default.
- W2023786688 hasRelatedWork W2518079150 @default.
- W2023786688 hasRelatedWork W2529957164 @default.
- W2023786688 isParatext "false" @default.
- W2023786688 isRetracted "false" @default.
- W2023786688 magId "2023786688" @default.
- W2023786688 workType "article" @default.