【摘要】 La2 CuO4的结构中因存在键角为 180°的…Cu—O—Cu—O—Cu…链而表现出反铁磁性 .Zn2 + 或Mg2 + 取代Cu2 + 后就破坏了这种长程有序 ,使Cu2 + 的有效磁矩升高 ,并且在 77～ 30 0K温区内观察不到N啨ｅｌ态 .La2 Cu1 xNixO4没有电子自旋共振(ESR)响应 ,也观察不到其N啨ｅｌ态 .La2 Cu1 xMxO4(M =Zn2 + ,Mg2 + )有ESR响应 ,这种响应很可能是由拉长的CuO6 八面体产生的 .采用常规的物理方法如X 射线粉末衍射 (XRD)和电子自旋共振等对样品进行了表征更多还原

【Abstract】 La 2CuO 4 is antiferromagnetic due to the existence of …Cu—O—Cu—O—Cu… chainlike structure whose bond angle is 180°.The substitution of Cu 2+ by Zn 2+ or Mg 2+ frustrates this long range ordering and raises the effective magnetic moment of Cu 2+ ,and the Néel state can not be observed in a temperature range of 77～300?K.La 2Cu 1 x Ni x O 4 is ESR silent and its Néel state can not be observed either.La 2Cu 1 x M x O 4(M=Zn 2+ ,Mg 2+ )give ESR signals which are supposed to be induced by the elongated CuO 6 octahedron. Samples were characterized by conventional physical techniques such as X ray diffraction(XRD),electron spin resonance(ESR)and so on.更多还原