Cai Zhi-rang, Guo Huan-yin, Liu Ning, Zhang Yu-heng
Materials Research Laboratory, Suzhou College, Suzhou 234000, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2007 Feb;27(2):223-7.
Polycrystalline samples of La0.3Ca0.7Mn(1-x)W(x)O3 (0.00 < or = x < or = 0.15) were prepared by conventional solid-state reaction method. The influence of W doping at Mn site on the magnetic transition of La0.3Ca0.7Mn(1-x)W(x)O3 system was studied by the measurements of magnetization-temperature (MT) curves, magnetization-magnetic intensity (MH) curves, and ESR spectra. The results show that, with the increase in W doping amount, the magnetic transition of the system exhibits a complicated charge process, when the doping amount is 0.00 < or = x < or = 0.08, the charge-ordering (CO) phase exists in the system, AFM/CO states coexist below the transition temperature, and the charge-ordering temperature (Tco) goes up with the increase in W doping content; when x > or = 0.12, the charge ordering (CO) state of the system weakens and melts, and paramagnetism-ferromagnetism (PM-FM) transition exists at extremely low temperature.
采用传统的固相反应法制备了La0.3Ca0.7Mn(1-x)W(x)O3（0.00≤x≤0.15）的多晶样品。通过测量磁化强度-温度（MT）曲线、磁化强度-磁场强度（MH）曲线和电子自旋共振（ESR）谱，研究了在Mn位点掺杂W对La0.3Ca0.7Mn(1-x)W(x)O3体系磁转变的影响。结果表明，随着W掺杂量的增加，体系的磁转变呈现出复杂的电荷过程，当掺杂量为0.00≤x≤0.08时，体系中存在电荷有序（CO）相，在转变温度以下AFM/CO态共存，且电荷有序温度（Tco）随W掺杂含量的增加而升高；当x≥0.12时，体系的电荷有序（CO）态减弱并消失，在极低温度下存在顺磁-铁磁（PM-FM）转变。
