We have determined the temperature dependence of the electrical conductivity σ(N, B, T) of nominally uncompensated, neutron-transmutation-doped (NTD)70Ge:Ga samples in magnetic fields up to B = 8 T at low temperatures (T = 0.05-0.5 K) to investigate both the doping-induced metal-insulator transition (MIT), σ(N,B,0) ∞ (N - Nc)μ, and the magnetic-field-induced MIT, σ(N, B, 0) ∞ (Bc - B)μ + ′. Our experimental results show that μ = μ′ = 1.1 ± 0.1 in sufficiently large magnetic fields.
- Critical exponent
- Metal-insulator transition
- Neutron-transmutation doping
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering