Scanning measurement of Seebeck coefficient of a heated sample
AssigneeCalifornia Institute of Technology
InventorsG. Jeffrey Snyder, Shiho Iwanaga
Life of this patent
Estimating the term…
Abstract
A novel scanning Seebeck coefficient measurement technique is disclosed utilizing a cold scanning thermocouple probe tip on heated bulk and thin film samples. The system measures variations in the Seebeck coefficient within the samples. The apparatus may be used for two dimensional mapping of the Seebeck coefficient on the bulk and thin film samples. This technique can be utilized for detection of defective regions, as well as phase separations in the sub-mm range of various thermoelectric materials.
Claims21
An apparatus for measuring a Seebeck coefficient of a sample, comprising:
- a mount stage for the sample, the mount stage having a heater for heating a back surface of the sample;
- a first un-heated thermocouple probe having a first contact point where temperature and voltage are measured;
- a second thermocouple probe having a second contact point where temperature and voltage are measured, the second contact point disposed at a fixed point against the sample distal from the first contact point;
- and
- a motorized stage supporting the first thermocouple probe for positioning the first contact point of the first thermocouple probe at different locations on a front surface of the sample;
- wherein contact between the first thermocouple probe and the sample creates a local cold spot at the first contact point on the sample and the Seebeck coefficient of the sample proximate to the second thermocouple probe for each of the different locations on the front surface of the sample.
method of measuring a Seebeck coefficient of a sample, comprising:
- heating a back surface of the sample with a heater on a mount stage, the mount stage supporting the sample;
- measuring temperature and voltage at a first contact point of a first un-heated thermocouple probe such that contact between the first thermocouple probe and the sample creates a local cold spot at the first contact point on the sample;
- measuring temperature and voltage at a second contact point of a second thermocouple probe substantially simultaneously with measuring of the first thermocouple probe, the second contact point disposed at a fixed point against the sample distal from the first contact point;
- positioning the first contact point of the first thermocouple probe at different locations on a front surface of the sample with a motorized stage supporting the first thermocouple probe;
- and
- determining the Seebeck coefficient of the sample proximate to the first contact point from probe and the temperature and voltage measured from the second thermocouple probe for each of the different locations on the front surface of the sample.
An apparatus for measuring a Seebeck coefficient of a sample, comprising:
- a mount stage means for supporting the sample heating a back surface of the sample;
- a first un-heated thermocouple probe means for measuring temperature and voltage at a first contact point;
- a second thermocouple probe means for measuring temperature and voltage at a second contact point, the second contact point disposed at a fixed point against the sample distal from the first contact point;
- and
- a motorized stage means for supporting the first thermocouple probe means and for positioning the first contact point of the first thermocouple probe means at different locations on a front surface of the sample;
- wherein contact between the first thermocouple probe means and the sample creates a local cold spot at the first contact point on the sample and the Seebeck coefficient of the sample proximate to the first contact point is determined from the temperature and voltage measured from the first thermocouple probe means and the temperature and voltage measured from the second thermocouple probe means for each of the different locations on the front surface of the sample.
Dependencies are inferred from the claim text.