SIFAT ELEKTRON ATOM Mn DI STRUKTUR PEROVSKITE PADA KRISTAL TUNGGAL La2-2xSr1+2xMn2O7 (x= 0,40)[Electron Properties of Mn Atom on Perovskite Structure of La2-2xSr1+2xMn2O7 (x= 0,40) Single Crystal]

Abstract

Mn-oxide materials have long been known to have large magnetoresistance properties. The world's attention increasingly focused on the structure of perovskite especially on the Mn-oxide material, to study the physical properties of the elektron. La2-2xSr1 xMn2O7 (LSMO 327, n = 2) which has 2 layers of Mn-O adjacently having the largest magnetoresistance properties (Colossal magnetoresistance, CMR) than in groups of n = 1, and n = . To investigate the nature of CMR, we analyzed the electric and magnetic properties by measuring resistivity, magnetoresistance and magnetization. According to the results, the sampel is seen to have largest magnetoresistance properties at 121 K. At temperaturs below 121 K, this material is seen to be conductor, and to be isolator above 121 K. According to magnetization analysis, this material is seen to be paramagnetic at temperatur above 200 K, anti-ferromagnetic at temperatur 121 K – 200 K, and the mixed of anti-ferromagnetic and ferromagnetic at temperaturs below 121 K.