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论文类型：期刊论文

发表时间：2005-09-01

发表刊物：CHINESE PHYSICS LETTERS

收录刊物：SCIE、ISTIC、Scopus

卷号：22

期号：9

页面范围：2429-2432

ISSN号：0256-307X

摘要：A microcalorimeter is studied for testing heat capacity of thin films. The microcalorimeter is a suspended membrane supported by six microbridges, which is fabricated by the front-side surface micromachining. Compared to the bulk micro-machined one, the microcalorimeter has excellent mechanical strength and precisely controlled pattern size as well as good thermal characteristics that are essential to a microcalorimeter. The heating rate of the microcalorimeter is up to 2 x 10(5) K/s with 4.5 mW heating power in vacuum, and the heat capacity of the corresponding empty microcalorimeter is about 23.4 nJ/K at 300K. By a pulse calorimetry, the heat capacity of Al thin films with thickness of 40-1150 nm are measured in the temperature range from 300K to 420K in vacuum. The mass of each sample is evaluated and the specific heat capacity is calculated. The results show that specific heat capacity of the 1150-nm Al film agrees well with the data of bulk Al reported in the literature. For the thinner films, enhanced heat capacity is observed.