Phase separation in paramagnetic Eu0.6La0.4−xSrx

Electron paramagnetic resonance study of (La0.33Sm0.67)0.67Sr0.33−Ba MnO3 (x<0.1): Griffiths phase

“…4) Intense lines, corresponding to Griffiths phase similar to those observed in the samples with x ¼0.03 and 0.06, were observed along with the paramagnetic lines at lower fields over a wide temperature range, up to room temperature. This behavior is similar to that, observed for EPR signal in the paramagnetic phase in Eu 0.6 La 0.4 À x Sr x MnO 3 [18] for samples with x from x ¼0.13 to x¼0.2. Paramagnetic and ferromagnetic phases should co-exist in this sample To this end, it is argued in [18] that possibly the magnetic Eu 3 þ ions favor a stabilization of ferromagnetic state in Eu 0.6 La 0.4 À x Sr x MnO 3 , and thus increase the intensity of EPR signals due to Griffiths phase signals over a wide temperature region.…”

“…This behavior is similar to that, observed for EPR signal in the paramagnetic phase in Eu 0.6 La 0.4 À x Sr x MnO 3 [18] for samples with x from x ¼0.13 to x¼0.2. Paramagnetic and ferromagnetic phases should co-exist in this sample To this end, it is argued in [18] that possibly the magnetic Eu 3 þ ions favor a stabilization of ferromagnetic state in Eu 0.6 La 0.4 À x Sr x MnO 3 , and thus increase the intensity of EPR signals due to Griffiths phase signals over a wide temperature region. The transition temperature to ferromagnetic phase is difficult to determine as the ferromagnetic lines are presumably masked by the predominant lines due to Griffiths phase, but by extrapolation it appears to be about 125 K (see Fig.…”

Structural first-order transformation in La2/3Ba1/3MnO3: ESR study

“…As a result, in real samples, the transition into magnetically ordered phase is often broadened and characterized by a coexistence of high-temperature (paramagnetic) and lowtemperature magnetically ordered phases over a wide temperature range. The persistence of paramagnetic phase down to the lowest temperatures was experimentally confirmed for various compositions of doped manganites, in particular, for those for which the ground state is ferromagnetic [2,34,41,42,46]. In our case, it is expected that the residual paramagnetic phase is mainly located within the intergrain region.…”

“…The PM signal is also slightly shifted to smaller fields, and at temperatures of about 260 K it starts to distort (Fig. 5), as is often observed in doped manganites [27,41,42]. It is noteworthy that the presence of paramagnetic phase below the point of the nucleation of magnetically ordered phase is not unexpected phenomenon for the doped manganite samples.…”

“…Such a signal was observed on the obtained spectra at H res FM of about 8 kOe). In addition to the FM signals, a wide paramagnetic (PM) line (H res PM $ 4 kOe) is present, associated with the response from paramagnetic regions [41][42][43].…”