Electrical Resistivity Anomalies in Some High - Crystalline Titanium-Aluminum and Vanadium - Alloys.
The electrical resistivity (rho) and magnetoresistivity (DELTA)(rho)(H)/(rho) have been measured at 0 (LESSTHEQ) H (LESSTHEQ) 125 kG and 1.2 (LESSTHEQ) T (LESSTHEQ) 4.2 K for the random solid-solution transition-metal-base alloys Ti(,100-x) Al(,x) with 0 (LESSTHEQ) x (LESSTHEQ) 25.3 at .%; V(,100-x) Al(,x) with 0 (LESSTHEQ) x (LESSTHEQ) 22.9 at .%; and (Ti(,70) V(,30.))(,100-x) Al(,x) with x = 0, 10, and 15 at .%. The normal-state electrical resistivities of the specimens range between 3 and 200 (mu)(OMEGA) cm. At liquid-helium temperatures T of 1-4 K and in applied magnetic fields H up to 125 kilogauss we observe (a) anomalous negative temperature coefficients of electrical resistivity dln(rho)/dT, and (b) anomalous negative magnetic coefficients of electrical resistivity dln(rho)/dH. Both these coefficients become more negative with increase of (rho) in the range (rho) = 30 - 200 (mu)(OMEGA) cm. These low-temperature thermal and magnetic "Mooij correlations" are shown to be roughly consistent with Kawabata's weak-localization theory for bulk alloys. Analysis of the data for TiAl and TiVAl alloys within the Kawabata -theory framework suggests inelastic scattering times (tau)(,i) (PROPORTIONAL) T('-1) with (tau)(,i)(1.2K) (DBLTURN) 5 x 10('-12) sec for the higher resistivity alloys.
- Pub Date:
- Physics: Condensed Matter