Acta Metallurgica Sinica (English Letters) ›› 2009, Vol. 22 ›› Issue (1): 51-57.DOI: 10.1016/S1006-7191(08)60070-8

• Research paper • Previous Articles     Next Articles

Effects of ferrites on magnetic transport properties in La2/3Sr1/3MnO3/ferrites composites

Zhengyou ZHOU1,Xiaoshan WU1,2,Jun DU2,Sheng XU2,Xiaojun BAI2,Guangsheng LUO1,Fengyi JIANG1   

  1. 1) School of Materials Science and Engineering, Nanchang University, Nanchang 330031, China
    2) Nanjing National Laboratory, Department of Physics,Nanjing University, Nanjing 210093, China
  • Received:2008-02-27 Revised:2008-06-27 Online:2009-02-25 Published:2009-10-10
  • Contact: Zhengyou ZHOU

Abstract:

Effects of soft-magnetic MnZn ferrite (Mn0.5Zn0.5Fe2O4, MZF) and hard-magnetic Ba
ferrite (BaO?6Fe2O3, BaM) on the structure and magnetic transport properties of [La2/3Sr1/3MnO3]
(LSMO)/(x) [ferrites] (ferrites=MZF, BaM) composites have been investigated. It was found that the inclusion of MZF phase reduces
magnetization and ferromagnetic-paramagnetic transition temperature (Tc) of the composites. With increasing the content of the
dopants, the high-temperature magnetoresistance (MR) decreases, whereas low-temperature MR increases and reaches 42% at 150~K and
x=0.1. However, for the LSMO/BaM composites, magnetization and ferromagnetic-paramagnetic transition temperature (Tc)
decrease firstly as x<5 %, and then increase as x>5 %. The resistivity of the composites increases by five orders of magnitude
at x=1 % and is out of measured range at x=5 %. High magnetic field has little effect on the resistivity and magnetoresistance for
the composites with x>5 %, which may originate from the pinning effect of BaM grains.

 

Key words: Composites, Magnetoresistance, Spin-dependent scattering, tunneling effect