Parallel screen for rapid thermal characterization of materials

Abstract

A method and apparatus for high-throughput determination of phase change points of combinatorial libraries of metal alloys uses an infrared camera to monitor temperature-dependent changes in emissivity/reflectivity of the alloys. An infrared focal plane array monitors the emissivity/reflectivity changes over time, and the intensity of each heated member over time is correlated with temperature to detect the phase change points of the members.

What is claimed is:  
     
         1 . A system for determining phase change points of at least two members in a combinatorial library, comprising: 
 a temperature changer for changing the temperature of each member;    a detector for monitoring changes in radiation from each member and generating intensity data for each member based on the detected radiation, wherein the detector is adapted to monitor said at least two members simultaneously; and    a correlator for correlating the intensity data from the detector with the temperature of each member, wherein a radiation change in the member indicates a phase change point for that member.    
     
     
         2 . The system of  claim 1 , wherein the correlator correlates the intensity data of the detector with the temperature of each member by correlating the intensity data from the detector versus time and correlating the temperature of each member versus time.  
     
     
         3 . The system of  claim 1 , wherein the detector is a position sensitive detector.  
     
     
         4 . The system of  claim 1 , wherein the detector is a plurality of single member detectors.  
     
     
         5 . The system of  claim 1 , wherein the detector is a focal plane array.  
     
     
         6 . The system of  claim 5 , wherein the focal plane array is a visible-mid-infrared focal plane array.  
     
     
         7 . A system for determining phase change points of at least two members in a combinatorial library, comprising: 
 a substrate having said at least two members disposed thereon;    a temperature changer for changing the temperature of each member on the substrate;    a detector for monitoring changes in radiation for each member and for generating intensity data based on the detected radiation; and    a correlator for correlating the intensity data from the detector with the temperature of each member, wherein a radiation change in the member indicates a phase change point for that member.    
     
     
         8 . The system of  claim 7 , wherein the correlator correlates the intensity data from the detector with the temperature of each member by correlating the intensity data from the detector versus time and correlating the temperature of each member versus time.  
     
     
         9 . The system of  claim 7 , wherein the temperature changer changes the temperature of the substrate, the detector monitors radiation changes of the substrate and generates intensity data based on the detected radiation, and wherein the correlator correlates the intensity data from the detector with the temperature of each sample by correlating the difference between the intensity data for each member and the intensity data for the substrate versus time and the intensity data for the substrate versus temperature.  
     
     
         10 . The system of  claim 9 , wherein the correlator correlates the intensity of the member with temperature by: 
 determining a calibration curve correlating the radiation intensity of the substrate and the temperature of the substrate;    measuring the radiation intensity versus time of each member and the substrate; and    calculating the ratio between the radiation intensity versus time of each member and the radiation intensity versus time of the substrate, wherein a change in the ratio for one of said members indicates the phase change point of that member.    
     
     
         11 . The system of  claim 7 , wherein the system characterizes said at least two members in a parallel fashion.  
     
     
         12 . The system of  claim 7 , wherein the system characterizes said at least two members in a rapid serial fashion.  
     
     
         13 . The system of  claim 10 , wherein the system determines phase change points at a rate of at least 60 samples/second.  
     
     
         14 . The system of  claim 7 , wherein the substrate is made of amorphous carbon.  
     
     
         15 . The system of  claim 7 , further comprising a capping layer deposited on top of said at least two members on the substrate.  
     
     
         16 . The system of  claim 7 , wherein the temperature changer is a substrate heater that heats the substrate, which in turn heats said at least two members.  
     
     
         17 . The system of  claim 16 , wherein the substrate heater is a low thermal mass heater.  
     
     
         18 . The system of  claim 16 , wherein the heater is a graphite heater.  
     
     
         19 . The system of  claim 16 , wherein the heater is a current source that applies current through at least one of the substrate and said at least two members to heat the members.  
     
     
         20 . The system of  claim 7 , wherein the detector is a position sensitive detector.  
     
     
         21 . The system of  claim 7 , wherein the detector is a plurality of single member detectors.  
     
     
         22 . The system of  claim 7 , wherein the detector is a focal plane array.  
     
     
         23 . The system of  claim 7 , wherein the focal plane array is a visible-mid-infrared focal plane array.  
     
     
         24 . The system of  claim 7 , further comprising a vacuum chamber surrounding the substrate and the heater.  
     
     
         25 . A system for determining phase change points of a plurality of members in a combinatorial library, comprising: 
 a temperature changer for changing the temperature of each member;    a detector for monitoring changes in radiation for each member and for generating intensity data based on the detected radiation; and    a correlator for correlating the intensity data from the detector with the temperature of each member, wherein a radiation change in the member indicates a phase change point for that member,    wherein the system determines phase change points at a rate of at least  60  samples/second.    
     
     
         26 . The system of  claim 25 , wherein the correlator correlates the intensity data from the detector with the temperature of each member by correlating the intensity data from the detector versus time and correlating the temperature of the member versus time.  
     
     
         27 . The system of  claim 25 , further comprising a substrate that supports the plurality of members, wherein the temperature changer changes the temperature of the substrate, the detector monitors changes in radiation for the substrate and generates intensity data based on the detected radiation, and wherein the correlator correlates the intensity data from the detector with the temperature of the members by correlating the difference between the intensity data for each member and the intensity data for the substrate versus time and the intensity data for the substrate versus temperature.  
     
     
         28 . The system of  claim 25 , wherein the system characterizes said plurality of members in a parallel fashion.  
     
     
         29 . The system of  claim 25 , wherein the system characterizes said plurality of members in a rapid serial fashion.  
     
     
         30 . A system for determining a phase change point of a member, comprising: 
 a temperature changer for changing the temperature of the member;    a detector for monitoring changes in radiation from the member and for generating intensity data for the member based on the detected radiation; and    a correlator for correlating the intensity data from the detector with the temperature of the member, wherein a radiation change in the member indicates a phase change point for the member.    
     
     
         31 . The system of  claim 30 , wherein the correlator correlates the intensity data from the detector with the temperature of the member by correlating the intensity data from the detector versus time and correlating the temperature of the member versus time.  
     
     
         32 . The system of  claim 30 , further comprising a substrate that supports the member, and wherein the correlator correlates the intensity data from the detector with the temperature of the member by correlating the difference between the intensity data for the member and the intensity data for the substrate versus time and the intensity data for the substrate versus temperature.  
     
     
         33 . A system for determining melting points of a plurality of materials in a combinatorial library, comprising: 
 a conductive substrate having a plurality of member materials disposed thereon;    a low thermal mass heater that supports the substrate and heats the plurality of member materials;    a vacuum chamber surrounding the substrate, the plurality of member materials, and the heater;    an infrared camera positioned over the substrate and the plurality of member materials, the infrared camera having a focal plane array for monitoring changes in radiation of the plurality of member materials over time as they are heated by the heater and generating image data; and    a computer that obtains the image data from the focal plane array and correlates the radiation intensities of the plurality of member materials with temperature, wherein a radiation change in the member material indicates a melting point for that member material.    
     
     
         34 . The system of  claim 33 , wherein the focal plane array is a visible-mid-infrared focal plane array.  
     
     
         35 . The system of  claim 33 , wherein the computer correlates the intensity of the member with temperature by: 
 determining a calibration curve correlating a radiation intensity of the substrate and the temperature of the substrate;    measuring the radiation intensity versus time of each of the plurality of members and the substrate; and    calculating the ratio between the radiation intensity versus time of each of the plurality of members and the radiation intensity versus time of the substrate, wherein a change in the ratio for a given member indicates the melting point of that member.    
     
     
         36 . A method for determining a phase change point of a member, comprising the steps of: 
 changing the temperature of the member;    monitoring changes in radiation from the member;    generating intensity data for the member based on the radiation changes detected in said monitoring step;    correlating the intensity data with the temperature of the member, wherein a radiation change in the member indicates a phase change for the member.    
     
     
         37 . The method of  claim 36 , wherein the correlation step correlates the intensity data with the temperature of the member by correlating the intensity data from the detector versus time and correlating the temperature of the member versus time.  
     
     
         38 . The method of  claim 36 , further comprising the step of depositing the member on a substrate, and wherein the changing step includes changing the temperature of the substrate, the monitoring step includes monitoring changes in radiation for the substrate, the generating step generates intensity data and the correlating step correlates the intensity data with the temperature of the member by correlating the difference between the intensity data for the member and the intensity data for the substrate versus time and the intensity data for the substrate versus temperature.  
     
     
         39 . The method of  claim 38 , wherein the depositing step deposits a plurality of members on the substrate using combinatorial techniques.  
     
     
         40 . The method of  claim 38 , wherein the substrate is electrically conductive, and wherein the heating step includes the step of passing a current through at least one of the substrate and the member.  
     
     
         41 . The method of  claim 36 , wherein the changing step includes heating the substrate on a low thermal mass heater.  
     
     
         42 . The method of  claim 36 , further comprising the step of depositing the member on the substrate, and wherein the correlating step includes the steps of: 
 determining a calibration curve correlating a radiation intensity of the substrate and the temperature of the substrate;    measuring the radiation intensity versus time of the member and the substrate; and    calculating the ratio between the radiation intensity versus time of the member and the radiation intensity versus time of the substrate, wherein a change in the ratio for a given member indicates the phase change of that member.