An ac calorimeter for measuring heat capacity of free‐standing liquid‐crystal films

1991 ◽  
Vol 62 (2) ◽  
pp. 415-421 ◽  
Author(s):  
R. Geer ◽  
T. Stoebe ◽  
T. Pitchford ◽  
C. C. Huang
Keyword(s):  
Heat Capacity ◽  
Liquid Crystal ◽  
Free Standing ◽  
Liquid Crystal Films ◽  
Crystal Films

Unusual Thickness-Dependent Heat-Capacity Anomalies in Free-Standing Hexatic Liquid-Crystal Films

2002 ◽  
Vol 88 (8) ◽  
Author(s):  
C. Y. Chao ◽  
C. R. Lo ◽  
P. J. Wu ◽  
T. C. Pan ◽  
M. Veum ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Liquid Crystal ◽  
Free Standing ◽  
Liquid Crystal Films ◽  
Crystal Films

Heat-Capacity Study of Free-Standing Liquid-Crystal Films

1986 ◽  
Vol 57 (10) ◽  
pp. 1239-1242 ◽  
Author(s):  
T. Pitchford ◽  
C. C. Huang ◽  
R. Pindak ◽  
J. W. Goodby
Keyword(s):  
Heat Capacity ◽  
Liquid Crystal ◽  
Free Standing ◽  
Liquid Crystal Films ◽  
Crystal Films

Unusual Thickness-Dependent Heat-Capacity Anomaly in Free-Standing Hexatic Liquid-Crystal Films

2004 ◽  
Vol 412 (1) ◽  
pp. 385-392
Author(s):  
C. Y. Chao ◽  
T.C. Pan ◽  
C. R. Lo ◽  
M. Veum ◽  
C. C. Huang ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Liquid Crystal ◽  
Free Standing ◽  
Liquid Crystal Films ◽  
Crystal Films ◽  
Heat Capacity Anomaly

Thermal Property Evolution Toward Effectively Two-Dimensional Substrate-Free Systems

1989 ◽  
Vol 177 ◽  
Author(s):  
R. Geer ◽  
T. Stoebe ◽  
C. C. Huang ◽  
R. Pindak ◽  
J. Goodby
Keyword(s):  
Heat Capacity ◽  
Liquid Crystal ◽  
Adiabatic Calorimeter ◽  
Two Dimensional ◽  
Limiting Behavior ◽  
Liquid Crystal Films ◽  
Smectic A ◽  
Surface Transition ◽  
Crystal Films ◽  
Molecular Layers

ABSTRACTA high-resolution differential quasi-adiabatic calorimeter has been developed to investigate the physical properties of freestanding liquid-crystal films. Our recent heat-capacity studies near the smectic-A-hexatic-B transition of both 65OBC and 46OBC freestanding films clearly demonstrate the evolution towards twodimensional limiting behavior in four-layer films. As the film thickness decreases towards four molecular layers, the heatcapacity anomalies first display separate peaks for the surface and interior transitions and then evolve to one dominated by the surface transition.

PHYSICAL PROPERTIES OF THIN SUBSTRATE-FREE LIQUID-CRYSTAL FILMS

1995 ◽  
Vol 09 (18n19) ◽  
pp. 2285-2319 ◽  
Author(s):  
T. STOEBE ◽  
C.C. HUANG
Keyword(s):  
Liquid Crystal ◽  
Two Dimensions ◽  
Calorimetric Data ◽  
Free Standing ◽  
Liquid Crystal Films ◽  
Ideal System ◽  
Crystal Films ◽  
Optical And Mechanical Properties ◽  
Molecular Layers ◽  
Physical Phenomena

Free-standing liquid-crystal films constitute a unique and phenomenally rich system in which a number of physical phenomena may be carefully studied. In particular, they provide an ideal system in which the novel theories of defect-mediated melting in two-dimensions (2D) may be tested. Calorimetric data is presented that indicate that such theories cannot adequately account for phase transitions in effectively 2D free-standing liquid-crystal films only two molecular layers in thickness. Extensive Monte Carlo simulation studies have therefore been performed on a trial Hamiltonian that couples herringbone order to the hexatic order. In a relatively large region of parameter space, the simulation yields heat-capacity consistent with our calorimetric data. These results are discussed in the context of existing data on the structural, optical, and mechanical properties of free-standing films.

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