The influence of sample geometry on measured physical properties (the magneto-Seebeck effect, Nernst effect, magnetoresistance effect, Hall effect, and thermal conductivity) in a magnetic field was investigated for a polycrystalline Bi-Sb sample. The polycrystalline Bi88Sb12 bulk sample was prepared using the spark plasma sintering method and annealing, and the physical properties obtained via measurements in magnetic fields of 5 T were compared with the simulated values obtained by the finite element method with considering various sample geometries. The appropriate shape required for the precise measurement of less than 2% error was found to be different for each physical property: the required aspect ratio of length l to width w is l/w > 0.57 for the magnetoresistance effect, l/w > 2.9 for the Hall effect, l/w > 4.2 for the two-wire magneto-Seebeck effect, l/w > 1.2 for the four-wire magneto-Seebeck effect, and l/w > 3.1 for the Nernst effect. We also found that a small error of less than 2% in the thermal conductivity measurement requires Ks/Kw > 27, where Ks and Kw represent the thermal conductance of sample and that of lead wire, respectively.
