April 2, 2010
      
                  
        
  Author(s)
  Winnie K. Wong-Ng,   Stevce  Stefanoski,   James A. Kaduk,   Qingzhen  Huang,   Clifford R. Bowers,   George S. Nolas,   Beekman  Mathew
 
       
            
    
    
        Structural analyses as well as low temperature thermal conductivity is reported for the new phase in the Na-Ge system, Na1-xGe3+z. Specimens were characterized by thermal analysis, conventional and synchrotron powder X-ray diffraction, neutron powder