HEAT-CAPACITY STUDY OF THE MELTING OF SUBMONOLAYER BUTANE FILMS ABSORBED ON GRAPHITE

被引:6
作者
ALKHAFAJI, MT [1 ]
MIGONE, AD [1 ]
机构
[1] SO ILLINOIS UNIV,MOLEC SCI PROGRAM,CARBONDALE,IL 62901
来源
PHYSICAL REVIEW B | 1993年 / 48卷 / 03期
关键词
D O I
10.1103/PhysRevB.48.1761
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
We have used ac calorimetry to study the melting transition of submonolayer butane films adsorbed on graphite. We investigated eight surface coverages ranging from n = 0.56 to n = 0.89 for temperatures between 98 and 126 K. We find one single, asymmetric, heat-capacity peak at melting. The melting-peak height is typically 15 in units of C/Nk(B) (where C is the total heat capacity of the film and N the number of butane molecules), and the peak temperature is 112.6+/-0.3 K. We identify the transition as first order. Our heat-capacity results are in good agreement with the elastic neutron-scattering results as well as with very recent computer simulations for this system. We also compare our results with predictions by Janke and Kleinert that the monolayer melting transition changes from first order to continuous as the adsorbed molecules studied go from spherical to elongated.
引用
收藏
页码:1761 / 1764
页数:4
相关论文
共 22 条
  • [1] HEAT-CAPACITY STUDY OF ACETYLENE ON GRAPHITE
    ALKHAFAJI, MT
    MIGONE, AD
    [J]. PHYSICAL REVIEW B, 1992, 45 (10): : 5729 - 5732
  • [2] LIQUIDS, CRYSTALS AND LIQUID-CRYSTALS
    BROCK, JD
    BIRGENEAU, RJ
    LITSTER, JD
    AHARONY, A
    [J]. PHYSICS TODAY, 1989, 42 (07) : 52 - 59
  • [3] CHAN MHW, 1991, NATO ADV SCI I B-PHY, V267, P1
  • [4] CHENG A, IN PRESS LANGMUIR
  • [5] HEAT-CAPACITY ANOMALY FROM 4-LAYER LIQUID-CRYSTAL FILMS
    GEER, R
    HUANG, CC
    PINDAK, R
    GOODBY, JW
    [J]. PHYSICAL REVIEW LETTERS, 1989, 63 (05) : 540 - 543
  • [6] MELTING MECHANISM IN MONOLAYERS OF FLEXIBLE ROD-SHAPED MOLECULES
    HANSEN, FY
    TAUB, H
    [J]. PHYSICAL REVIEW LETTERS, 1992, 69 (04) : 652 - 655
  • [7] MONTE-CARLO STUDY OF 2-STEP DEFECT MELTING
    JANKE, W
    KLEINERT, H
    [J]. PHYSICAL REVIEW B, 1990, 41 (10) : 6848 - 6863
  • [8] JANKE W, 1988, PHYS REV LETT, V61, P2324
  • [9] EXPERIMENTAL-EVIDENCE OF CONTINUOUS MELTING OF ETHYLENE ON GRAPHITE
    KIM, HK
    ZHANG, QM
    CHAN, MHW
    [J]. PHYSICAL REVIEW LETTERS, 1986, 56 (15) : 1579 - 1582
  • [10] ORDERING, METASTABILITY AND PHASE-TRANSITIONS IN 2 DIMENSIONAL SYSTEMS
    Kosterlitz, JM
    Thouless, DJ
    [J]. JOURNAL OF PHYSICS C-SOLID STATE PHYSICS, 1973, 6 (07): : 1181 - 1203