No abstract

No abstract

No abstract

No abstract

Temperature and field dependent magnetic and transport measurements on a polycrystalline sample of Sr 1.6 La 1.4 Mn 2 O 7 reveal distinct magnetic peaks above the ferromagnetic ordering temperature T C % 90 K. The magnetic moment of the subsidiary phases identified as perovskitic impurities by a relation between the volume fraction and the corresponding magnetic moment does not couple with that of Sr 1.6 La 1.4 Mn 2 O 7 in the high temperature range. This is evidenced by the presence of two slopes, dM/dH, in the M(H) curves and two different field dependences, H and H 2 , in the r(H) curves. On the other hand, a simple slope, dM/dH, in the low temperature regime hints at an exchange coupling between the magnetic moments of the two phases.