Correlation between phase competition and the nucleation of a Griffiths-like phase in (La_1-yPr_y)_0.7Ca_0.3Mn^16/18O₃

Abstract

85, the GP is suppressed. These data, combined with previous neutron diffraction measurements, enable a phase diagram summarizing the evolution of the GP with composition to be constructed for this system; in particular, it shows that the disorder relevant for the establishment of such a phase is linked closely to the relative volume fractions of the phase separated antiferromagnetic and ferromagnetic components, even when the recently estimated double exchange (DE) linked percolation threshold is exceeded. The influence of electron-phonon coupling can also be seen through oxygen isotope effects.

Griffiths phase-like behavior and spin-phonon coupling in double perovskite Tb2NiMnO6

“…The magnetic susceptibility of Tb 2 NiMnO 6 at H ¼ 20 Oe was analyzed using the power law with great care to avoid an incorrect estimation of T R C ; this can lead to erroneous values of k. Recent literature that offers a better protocol to perform the analysis was adopted to estimate T R C and k in the purely paramagnetic region. 20,21 Following the procedure reported in literature, 19,20 we first estimated the value of T R C in the purely paramagnetic region above T G . A value of 56 K for T R C was estimated in this way that can be compared with that obtained by Zhou et al 20 Using this value of T R C , fitting was performed in the GP regime to obtain a value of 0.88 for k. The result of the analysis is presented in Fig.…”

Antiferromagnetic rare region effect in Pr0.5Ca0.5MnO3

“…We further analyze the data by fitting the temperature dependence of inverse dc magnetic susceptibility using the relation [40][41][42][43][44] χ…”

Anomalous behavior above the Curie temperature in (Nd1−xGdx)0.55Sr0.45MnO3 (x = 0, 0.1, 0.3 and 0.5)

“…16 By contrast, in La 1Àx Ba x MnO 3 , the quenched disorder arising from the size variance of La/Ba atoms was reported to be responsible for the development of the GP, 17 while in (La 1Ày Pr y ) 0.7 Ca 0.3 Mn 16/18 O 3 , a close relationship between the FM-AFM phase competition and the nucleation of the GP was observed, where the GP appears as the FM phase dominates and disappearing as the AFM phase dominates over the FM one. 31 In fact, the Rietveld renements carried out in our previous work, 24 reveal that the MnO 6 octahedra are not regular with higher dispersion in the magnetically active Mn-O-Mn bond distances and bond angles. The average hMn-Oi bond lengths show an almost negligible dependence on x, a result that is not surprising considering their ensitiveness to the J-T active Mn 3+ oxidation state, which remains unchanged for this series of compounds.…”