Effect of spin substitution on stripe order in La1.875Ba0.125Cu1-yMyO4 (M = Zn or Ni) - art. no. 140506

The destruction of stripe order by Zn (S=0) and the formation of a new phas e by Ni (S=1) are demonstrated directly from the substitution dependence of the electronic coefficient of specific heat gamma in La1.875Ba0.125Cu1-yMy O4 (M=Zn or Ni). In the Zn-substitution case, gamma, which is strongly supp ressed by stripe phase formation, increases to a value that corresponds to the state where there is no stripe order. In the Ni-substitution case, gamm a saturates at nearly half the value of the Zn-substitution case. The diffe rence can be explained by a difference in the spin interactions between the substituent atom and the nearest neighbor Cu atoms, indicating that spin i nteraction plays an important role in the formation of charge stripes.