In-plane electrical resistivity under strong magnetic fields up to 27 T in La_2-xBa_xCuO₄ and La_2-xSr _xCuO₄ around x = 1/8

Magnetic-field effects on the so-called charge-spin stripe order, namely, the charge stripe order and spin stripe order in the La-214 system have been investigated from the in-plane electrical-resistivity, ρ_ab, measurements. In La_2-xBa_xCuO₄ (LBCO) with x = 0.10 and La_2-xBa_xCuO₄ with x = 0.115 where the incommensurate charge peaks are weak and unobservable in zero field from the elastic neutron-scattering measurements, respectively, the normal-state value of ρ_ab at low temperatures markedly increases with increasing field up to 27 T. As for x = 0.11 in LBCO where the charge stripe order is fairly stabilized in zero field, the increase in ρ_ab with increasing field is negligibly small. In conclusion, the magnitude of the increase in ρ_ab by the application of magnetic field is well correlated with the stability of the charge stripe order in zero field for the La-214 system around x = 1/8. Our understanding is as follows. When the charge-spin stripe order is not fully stable in zero field, magnetic field operates to stabilize the charge-spin stripe order. The value of ρ_ab increases with increasing field depending on the stability of the charge stripe order.