Structure and transport properties of LSMO

From the magnetic moment measurements shown in Fig. 2(c), a Curie temperature of Tc = 188 K can be derived by linear extrapolation of the inverse magnetic moment to zero. At temperatures slightly below Tc, the magnetic moment stays constant at about 3/4 of its low-temperature value, and the resistivity becomes metallic-like. Moreover, the CJT effect starts to decrease around Tc. As expected for this compound CO sets in at temperatures below TCo = 147 K. This leads to 

1 The slight orthorhombic distortion of LSMO which is present even above Tjt- leads to an orthorhombic unit cell with expanded lattice parameters a0 = Jla, b0 = -Jib, and c0 = 2c. Here a, b, and c denote the lattice constants of the (pseudo) cubic unit cell. 

2 The (x, y, z) coordinates which are used in this chapter actually form a different local coordinate system for each Mn site, in such a way that the occupied orbitals can always be expressed as either x2 — y2 or 3z2 — r2 instead of, for instance, 3x2 — r2. 

i7Mn03 [13] and in the ferromagnetic phase of Lao.825Sro.175Mno.94 Mgo.oeOs [14]. 

The fact that LSMO is ferromagnetic in the charge-ordered, insulating state is remarkable, since it indicates that the ferromagnetic interaction at low temperatures cannot arise from the double exchange mechanism. We note here that other 

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