2012/03/13 by S. Tagliati, V. M. Krasnov, A. Rydh · 57 citations
Chemistry · Physics and Astronomy · #Amplifier #Calorimeter (particle physics) #Force Microscopy Techniques and Applications #Heat capacity #Measuring instrument #Mechanical and Optical Resonators #Ranging #Resistive touchscreen #Temperature measurement #Thermal conductivity #Thermocouple #Thermometer #cond-mat.other #cond-mat.supr-con #physics.ins-det #thermodynamics and calorimetric analyses
paper · pdf · doi:10.1063/1.4717676
published in Review of Scientific Instruments 83(5), 055107 (American Institute of Physics) · Submitted to Review of Scientific Instruments
arxiv created 2012/03/13 · openalex publication_date 2012/05/01 · arxiv updated 2012/08/20 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A differential, membrane-based nanocalorimeter for general specific heat studies of very small samples, ranging from 0.5 mg to sub-μg in mass, is described. The calorimeter operates over the temperature range from above room temperature down to 0.5 K. It consists of a pair of cells, each of which is a stack of heaters and thermometer in the center of a silicon nitride membrane, in total giving a background heat capacity less than 100 nJ/K at 300 K, decreasing to 10 pJ/K at 1 K. The device has several distinctive features: (i) The resistive thermometer, made of a Ge(1 - x)Au(x) alloy, displays a high dimensionless sensitivity ∣dlnR∕dlnT∣ ≳ 1 over the entire temperature range. (ii) The sample is placed in direct contact with the thermometer, which is allowed to self-heat. The thermometer can thus be operated at high dc current to increase the resolution. (iii) Data are acquired with a set of eight synchronized lock-in amplifiers measuring dc, 1st and 2nd harmonic signals of heaters and thermometer. This gives high resolution and allows continuous output adjustments without additional noise. (iv) Absolute accuracy is achieved via a variable-frequency-fixed-phase technique in which the measurement frequency is automatically adjusted during the measurements to account for the temperature variation of the sample heat capacity and the device thermal conductance. The performance of the calorimeter is illustrated by studying the heat capacity of a small Au sample and the specific heat of a 2.6 μg piece of superconducting Pb in various magnetic fields.