Thermoelectric material and method for producing same

Abstract

A thermoelectric material has an average crystal particle size of at most 50 nm and has a relative density of at least 85%. A method of manufacturing a thermoelectric material includes the steps of preparing a fine powder and sintering or compacting the fine powder under a pressure of at least 1.0 GPa and at most 10 GPa.

1 . A thermoelectric material having an average crystal particle size of at most 50 nm and having a relative density of at least 85%.  
   
   
       2 . The thermoelectric material according to  claim 1 , wherein an EDS analysis of a grain boundary portion of said thermoelectric material shows that impurity elements have a detected intensity of at most one-fifth of a maximum detected intensity of an element among constituent elements of said thermoelectric material.  
   
   
       3 . The thermoelectric material according to  claim 1 , wherein said thermoelectric material has an electrical resistivity of at most 1×10 −3  Ωm.  
   
   
       4 . The thermoelectric material according to  claim 1 , wherein said thermoelectric material has a thermal conductivity of at most 5 W/mK.  
   
   
       5 . The thermoelectric material according to  claim 1 , wherein said thermoelectric material has a thermal conductivity of at most 1 W/mK.  
   
   
       6 . A method of manufacturing a thermoelectric material comprising the steps of: 
 preparing a fine powder; and    sintering or compacting said fine powder under a pressure of at least 1.0 GPa and at most 10 GPa.    
   
   
       7 . The method of manufacturing a thermoelectric material according to  claim 6 , further comprising the step of annealing polycrystalline body resultant from said sintering or compacting step.