Investigation of a Microcalorimeter for Thin-Film Heat Capacity Measurement
Investigation of a Microcalorimeter for Thin-Film Heat Capacity Measurement
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DOI：
10.1088/0256-307x/22/9/080
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发表时间：
2005-09
影响因子：
3.5
通讯作者：
Yubin Jun;Tang Zhen-an;Zhang Feng-tian;Wei Guang-fen;Wang Liding
中科院分区：
文献类型：
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作者：
Yubin Jun;Tang Zhen-an;Zhang Feng-tian;Wei Guang-fen;Wang Liding
研究了用微热量计测试薄膜热容的方法。微热量计是由6个微桥支撑的悬浮膜，通过前表面微加工制成。与本体微加工的微热量计相比，该微热量计具有优异的机械强度和精确控制的图案尺寸以及良好的热特性，这些都是微热量计所必需的。真空加热功率为4.5 mW时，该微热量计的加热速率可达2×105 K/s，在300 K时，相应的空微热量计的热容量约为23.4 nJ/K。用脉冲量热法测定了厚度为40 ~ 1150nm的铝薄膜在真空中300 ~ 420k温度范围内的热容。评估每个样品的质量并计算比热容。结果表明，1150 nm铝膜的比热容与文献中报道的大块铝的数据吻合较好。对于较薄的薄膜，观察到热容增强。
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 2×105 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 300 K. By a pulse calorimetry, the heat capacity of Al thin films with thickness of 40–1150 nm are measured in the temperature range from 300 K to 420 K 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.