  Magnetic-field effects on the charge-spin stripe order in La-214 high-Tc
cuprates have been investigated from measurements of the in-plane
electrical-resistivity, Rho_ab_. In La_2-x_Ba_x_CuO_4_ with x=0.10 and
La_2-x_Sr_x_CuO_4_ with x=0.115 where the incommensurate charge peaks are weak
and unobservable in zero field in elastic neutron-scattering measurements,
respectively, the normal-state value of Rho_ab_ at low temperatures markedly
increases with increasing field up to 27 T. For La_2-x_Ba_x_CuO_4_ with x=0.11
and Zn-substituted La_2-x_Sr_x_Cu_1-y_Zn_y_O_4_ with x=0.115 and y=0.02 where
the charge stripe order is fairly stabilized in zero field, on the other hand,
the increase in Rho_ab_ with increasing field is negligibly small. In
conclusion, 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 Rho_ab_ increases with increasing field depending on the stability of
the charge stripe order.
