四探针法测电阻率

141423141212r42r13r43r12ρIrJ22rIJπ=1ρε=J222rIπρε=drdV−=εrV∫∫∞−=rrVdrdVε)(0rIrV12)(πρ=44r12314)11(242122rrIV−=πρ5)11(243133rrIV−=πρ623)1111(2431342122rrrrIV+−−=πρ)1111(24313421223rrrrIV+−−=πρ71423723VS327IVS232πρ=848IVBS2302πρ=90B0B30102−×=BSIπ9I32310×V10cm23284pnnppnpn0.53SSRIVRS2lnπ=1010SRJx)(xN∫=JxSdxqxNR0)(1µ11q)(xNSRJx0N412550m(lmm)1002004232310-4V1V12345612341nn+pp+?2np3?198530-381985