Magnetic properties and Griffiths singularity in La0.45Sr0.55 Mn1−xCoxO3

Effects of non magnetic aluminum Al doping on the structural, magnetic and transport properties in La0.57Nd0.1Sr0.33MnO3 manganite oxide

“…The process reported in the literature most often is the doping of manganites with various elements in two different positions. These are called A-site [15][16][17] and B-site (or Mn-site) [18][19][20][21][22] substitution. It is believed that the study of the doping effects at the Mn site by other elements with different valences, electron configuration, ionic radius, and non-magnetic ions is very important because of the crucial role of Mn ions in the CMR materials.…”

“…The Curie temperature (TC) for La0.7Sr0.3Mn0.9B0.1O3 compounds with B = Mn, Cr, Al, Ga, Ni, Co, Cu, Fe[8,[18][19][20][21][22].…”

Double metal–insulator peaks and effect of Sm3+ substitution on magnetic and transport properties of hole-doped La0.85Ag0.15MnO3

“…However, it was suggested that the double exchange mechanism alone is not sufficient to explain the details of the observed resistivity behavior such as the insulating behavior above T c and the CMR phenomena. Some authors suggest that other factors such as electron-phonon coupling arising from the Jahn-Teller effect [5], phase separation [6][7][8][9][10] and Griffith's phase [11][12][13][14][15][16] may also play significant roles and should be considered for a more complete explanation of a variety of phenomena observed in manganites.…”

“…Besides the above, the presence of ferromagnetic, FM clusters in paramagnetic, PM region above T c has been suggested by several authors [11][12][13][14][15][16]. The region where minor FM phase coexist with the dominant PM phase in the region above T c and below the characteristic temperature, T G is called Griffith's phase [11][12][13][14][15][16].…”

“…The region where minor FM phase coexist with the dominant PM phase in the region above T c and below the characteristic temperature, T G is called Griffith's phase [11][12][13][14][15][16]. The T G is defined as the temperature corresponding to where the curve deviates from the linear behavior of the CurieWeiss law in the (w 0 ) À 1 versus temperature curve [11][12][13][14][15][16]. The existence of FM clusters in PM region was confirmed by EPR for (La 1/3 Sm 2/3 ) 2/3 Sr x Ba 0.33 À x MnO 3 [11] and by ESR for La 0.67 Ca 0.…”