tailieunhanh - Magnetic and magnetotransport properties of La0.7Ca0.3Mn1-x(Zn,Cu)xO3
Magnetic and magnetotransport properties of two perovskite manganite samples of and prepared by conventional solid-state reaction have been studied in detail. Experimental results revealed that the temperature dependences of magnetization and resistance varied strongly around the phase-transition temperature. Maximum magnetoresistance (MR) values of and under an applied field of 400 Oe were about % and %, respectively. The maximum magnetic-entropy change (ΔSM) was J/ for , and J/ for when the applied field was 45 kOe. Both the MR and ΔSM values obtained from two samples were smaller than those of the parent compound . This was due to the change in the Mn3+/Mn4+ ratio caused by Zn and Cu dopants, which led to a change in the type of the ferromagneticparamagnetic phase transition. | Magnetic and magnetotransport properties of (Zn,Cu)xO3
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