In this work, (La_0.6Ln_0.4)_0.67Ca_0.33MnO₃ (Ln=La, Pr, Nd and Sm) nanoparticles (NPs) synthesized by sol-gel process were investigated by electron spin resonance (ESR) in the temperature range 100–330 K. At the high temperature the ESR signals of La_0.67Ca_0.33MnO₃ (LCMO) NPs only consist of a single peak with Land g factor of 2.0. This signal is contributed from the paramagnetic (PM) Mn ions in the LCMO NPs. With decreasing the temperature the PM resonance line is split into two resonance lines, one is ferromagnetic (FM) resonance line shifting towards low field while the other is antiferromagnetic (AFM) resonance line moving to a high field. The resonance peak-to-peak spectra linewidth, increases monotonically with decreasing the temperature owing to the strong double exchange interactions below the Curie temperature (T _C). Resonance field is almost temperature independent in the PM phase whereas it drops fast at temperature below T _C. Consequently, the Land g factor in the PM region is very close to 2.0 whereas in the range of 2.17–2.47 under FM state due to the strong FM interactions. For the Pr (Nd)-doped LCMO NPs below T _C, their g values are in the range of 2.04–2.18 due to the substantial reduction of the FM interactions caused by the Pr (Nd)-doping at La-site. The g values of the Sm-doped LCMO NPs exhibit a slight fluctuation around 1.88 (but smaller than 2.0) within the measured temperature due to the existence of weak magnetic interactions under the PM states.

在这项工作中，式（Ia _0.6 LN _0.4）_0.67的Ca _0.33的MnO ₃通过溶胶-凝胶法合成的（Ln为镧，镨，钕和钐）纳米颗粒（NP）通过电子自旋共振（ESR）的温度范围内100调查–330 K。在高温下，La _0.67 Ca _0.33 MnO ₃ (LCMO) NPs的 ESR 信号仅由一个单峰组成，Land g系数 2.0。该信号来自 LCMO NP 中的顺磁性 (PM) Mn 离子。随着温度的降低，PM 共振线被分成两条共振线，一条是向低场移动的铁磁 (FM) 共振线，而另一条是向高场移动的反铁磁 (AFM) 共振线。共振峰-峰值的光谱线宽，随由于低于居里温度（强双交换相互作用的温度单调增加Ť _Ç）。共振场在 PM 阶段几乎与温度无关，而在温度低于T _{C 时}它迅速下降。因此，土地g由于强 FM 相互作用，PM 区域中的因子非常接近 2.0，而在 FM 状态下的范围为 2.17-2.47。对于低于T _C的 Pr (Nd) 掺杂 LCMO NP ，由于 La 位的 Pr (Nd) 掺杂导致 FM 相互作用显着减少，因此它们的g值在 2.04-2.18 的范围内。由于在 PM 状态下存在弱磁相互作用，Sm 掺杂的 LCMO NPs的g值在测量温度内表现出约 1.88（但小于 2.0）的轻微波动。