Browsing by Author "White, Mary Anne"
Now showing items 1-20 of 21
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Automated, small sample-size adiabatic calorimeter.
Van Oort, Michiel J. M.; White, Mary Anne (1987)An automated adiabatic calorimeter is described with an internal vol. of 5 cm3, operable at 30-380 K. One of the main advantages of this calorimeter over others in use is the shorter down time during sample changes, due ... -
A calorimetric investigation of the low-temperature phase transition in sodium hydroxide-d.
White, Mary Anne; Moore, Stanley A. (1986)The heat capacity of NaOD from 20 to 350 K is reported. An anomaly centered at 153.2 ± 0.1 K (?H = 131.1 ± 0.7 J/mol, ?S = 0.864 ± 0.005 J/K.mol) corresponds to the onset of a low-temp. antiferroelec. phase. This ... -
The heat capacities of thermomiotic ScF3 and ScF3–YF3 solid solutions
Romao, Carl; Morelock, Cody; Johnson, Michel; Zwanziger, Josef; Wilkinson, Angus; White, Mary Anne (Springer, 2015-05-01)Scandium trifluoride (ScF3) exists in a cubic ReO3 structure that exhibits negative thermal expansion from 10 to 1100 K, while substituted Sc1−x Y x F3 materials display the same behavior at room temperature but transition ... -
Heat capacity of gadolinium near the Curie temperature.
Bednarz, Grzegorz; Geldart, D. J. W.; White, Mary Anne (1993)High-resoln. ac calorimetric data near the Curie point are reported for several single crystals of gadolinium. The crit. temp. and the shape of the heat-capacity curve near Tc both depend on the sample-prepn. procedure, ... -
Heat capacity, lattice dynamics, and thermodynamic stability of the negative thermal expansion material HfMo2O8
Kennedy, Catherine A.; White, Mary Anne; Wilkinson, Angus P.; Varga, Tamas (2007-06)We explore the lattice dynamics of the negative thermal expansion material, cubic HfMo2O8, through analysis of its heat capacity (measured from 0.5 to 300 K) and its room-temperature Raman spectrum. Its heat capacity is ... -
High-resolution, high-sensitive ac calorimeter.
Bednarz, Grzegorz; Millier, Brian; White, Mary Anne (1992)A high-resoln., high-sensitivity, automated ac calorimeter capable of heat capacity measurements of very small samples (m < 20 mg) with a temp. resoln. of a few mK in the ac mode is described. This calorimeter also can be ... -
Investigation of factors affecting crystallization of cyclopentane clathrate hydrate
Whitman, Catherine A.; Mysyk, Roman; White, Mary Anne (2008-11)We report the results of systematic investigations of the influence of thermal history and other factors on crystallization of a model clathrate hydrate (cyclopentane hydrate) studied as water-in-oil and oil-in-water ... -
Low thermal conductivity of the negative thermal expansion material, HfMo2O8
Kennedy, Catherine A.; White, Mary Anne; Wilkinson, Angus P.; Varga, Tamas (2007-04)The thermal conductivity of the cubic polymorph of hafnium molybdate, HfMo2O8, was determined over the temperature range of 2-400 K. The values of thermal conductivity were low (0.64 +/- 0.15 W m(-1) K-1 at T=300 K for a ... -
The nature of ammonium ion disorder in ammonium tetrafluoroaluminate, NH4AlF4.
White, Mary Anne; Wagner, Brian D. (1985)To clarify previous conflicting reports concerning the existence of an order-disorder phase transition in NH4AlF4 at T ?150 K, the heat capacity of this compd. was measured from T = 15 to 305 K, by adiabatic calorimetry. ... -
Phase transitions in M(ClO4)2.6H2O (M = magnesium, zinc). Investigations by adiabatic calorimetry and infrared spectroscopy.
White, Mary Anne; Falk, Michael (1986)IR spectra of Mg(ClO4)2.6H2O at 10 K indicate a complex structure contg. at least 16 distinct types of H2O protons. At 107.9 K this structure transforms sharply to a much simpler disordered form (?Strans = 7.754 J K-1 ... -
Phase transitions in metal perchlorate hydrates: the supposed hydrate-to-pseudohydrate transformations.
Falk, Michael; Seto, Ping F.; White, Mary Anne (1984)A polemic. The hydrate-to-pseudohydrate transformations in metal perchlorate hydrates reported by M. B. Patel and H. D. Brist (ibid. 1983, 79, 4489) and Solid State Commun. (48, 139 (1983)) as well as the suggested ... -
A study of phase transitions in cadmium perchlorate hexahydrate (Cd(ClO4)2.6H2O) by adiabatic calorimetry and infrared spectroscopy.
White, Mary Anne; Falk, Michael (1985)A calorimetric study of Cd(ClO4)2.6H2O from 20 to 345 K shows 3 phase transformations, at 124.8, 238.45, and 271.62 K. IR spectra indicate that the low-temp. structure (below 124.8 K) contains 1 type of [Cd(OH2)6]2+, of ... -
Technique for determination of accurate heat capacities of volatile, powdered, or air-sensitive samples using relaxation calorimetry
Marriott, Robert A.; Stancescu, Maria; Kennedy, Catherine A.; White, Mary Anne (2006-09)We introduce a four-step technique for the accurate determination of the heat capacity of volatile or air-sensitive samples using relaxation calorimetry. The samples are encapsulated in a hermetically sealed differential ... -
Temperature dependence of thermal conductivity enhancement in single-walled carbon nanotube/polystyrene composites
Jakubinek, Michael B.; White, Mary Anne; Mu, Minfang; Winey, Karen I. (2010-02)The thermal conductivity of single-walled carbon nanotube (SWCNT)/polystyrene composites, prepared by a method known to produce a uniform distribution of SWCNT bundles on the micrometer length scale, was measured in the ... -
Thermal conductivities of a clathrate with and without guest molecules.
Zakrzewski, Marek; White, Mary Anne (1992)The thermal conductivities of Dianin's compd. [4-(p-hydroxyphenyl)-2,2,4-trimethylchroman] and its ethanol adduct in the temp. range 20-250 K are reported. This clathrate has the same stable structure both with and without ... -
Thermal conductivity of (Er1-xYx)(2)Ti2O7 pyrochlore oxide solid solutions
Bryan, Craig; Whitman, Catherine A.; Johnson, Michel B.; Niven, John F.; Murray, Patrick; Bourque, Alex; Dabkowska, Hanna A.; Gaulin, Bruce D.; White, Mary Anne (2012-08)The thermal conductivities of pyrochlore oxide solid solutions of general formula (Er1-xYx)(2)Ti2O7 with 0 <= x <= 1 have been determined for high-quality single crystals aligned along the [110] direction, over the ... -
Thermal, vibrational, and thermoelastic properties of Y2Mo3O12 and their relations to negative thermal expansion
Romao, Carl; Miller, Kimberley; Johnson, Michel; Zwanziger, Josef; Marinkovic, Bojan; White, Mary Anne (American Physical Society, 2014-07-21)Y2 Mo3O12, a material that exhibits negative thermal expansion (NTE) from 10 to 1173 K, offers an excellent opportunity to examine relationships between NTE and other physical properties over a wide temperature range. We ... -
A thermodynamic investigation of dynamical disorder in phase II of CBr4.
Michalski, Darek; White, Mary Anne (1995)CBr4 is an archetypal example of a pseudospherical mol. that can form an orientationally disordered phase (phase I, 320 K < T < 365 K). At lower temps., phase II is the stable phase; although it must be more ordered than ... -
X-ray absorption spectroscopy studies of local structure and electronic properties of NaxSi136 (0 < x < 24) clathrates
Ritchie, Andrew D.; MacDonald, Mark A.; Zhang, Peng; White, Mary Anne; Beekman, Matt; Gryko, Jan; Nolas, George S. (2010-10)We have probed both the local structure and the electronic properties of Na-containing type II Si clathrates by x-ray absorption spectroscopy. The near-edge region of the spectrum is particularly sensitive to the local ... -
X-ray absorption spectroscopy studies of local structure and electronic properties of NaxSi136 (0 < x < 24) clathrates.
Ritchie, Andrew D.; MacDonald, Mark A.; Zhang, Peng; White, Mary Anne; Beekman, Matt; Gryko, Jan; Nolas, George S. (2010)The local structure and electronic properties were probed of Na-contg. type II Si clathrates by x-ray absorption spectroscopy. The near-edge region of the spectrum is particularly sensitive to the local structure surrounding ...