INSTRUMENT AND METHOD FOR MEASURING ABSORPTION

摘要

PURPOSE: To measure absorbance with high resolution by applying energy to a sample and causing local heating thereof and then measuring the potential at a joint of a heat measuring chip while keeping the chip within about 10angstrom from a conductive surface. CONSTITUTION: A sample 10 is supported on a substrate 12 and applied, as required, with a conductive coating 11. A radiation 16 from a light source 15 is directed through the substrate 12 toward the sample 10 and a local temperature variation is caused on the surface by the incident energy. A three- dimensionally movable heat measuring chip 21 is positioned within about 10angstrom from a conductive surface by an x, y, z axis piezoelectric drive mechanism 20 and the interval is sustained using a tunneling current through a feedback loop. A switching device 30 is switched from tunneling mode to measuring mode depending on the thermal equilibrium. Consequently, the potential at the joint of the chip 21 and the conductive surface of the sample 10 can be measured by the detector 45.