Is a Griffiths Phase a Prerequisite for Colossal Magnetoresistance?

Abstract

Detailed measurements of the magnetic and transport behavior of the two La(1-x)Ca(x)MnO(3) single crystals exhibiting colossal magnetoresistance are summarized. The x=0.21 sample exhibits unusual exponents (delta = 20+/-1, gamma = 1.71+/-0.1, beta = 0.09+/-0.01, T(C) = 182+/-1 K) and, more importantly, a Griffiths phase characterized by an exponent lambda = 0.70+/-0.2. By contrast, the x=0.20 specimen displays Heisenberg model behavior with no evidence of such a phase. Thus while a Griffiths phase accounts for the behavior of La(1-x)Ca(x)MnO(3) near optimal doping, it does not appear to be a prerequisite for colossal magnetoresistance in this system.

Critical Behavior Near the Paramagnetic to Ferromagnetic Phase Transition Temperature in Sr1.5Nd0.5MnO4 Compound

“…In fact, such type of canting due to rareearth ion is indeed possible for manganites as also been reported in previous experimental results by Park et [46]. This compound presented a Griffiths phase in form of FM cluster system within a PM matrix is indicated by macroscopic magnetization experiments [47][48][49][50][51][52][53][54]. The magnetic anomaly is more obvious in the inverse susceptibility and its derivative as a function of temperature [27].…”

Magnetically doped semiconducting topological insulators

“…4(b) and 4(c), rather than displaying the parallel straight lines, both plots display some continuous curvatures, even in the saturation region up to 8000 Oe, and these effects turn to exclude the dominant long range interactions, as well as preclude us from giving an accurate estimation of the transition temperature. 44,47,56 In . The applied magnetic field is always perpendicular to the sample surface, and the field range which covers from À8000 Oe to 8000 Oe is high enough to saturate the magnetic moment.…”

Griffiths-like phase of magnetocaloricR5(SixGe1−x)Pereira1, Morellón2, Magén3 et al. 2010Phys. Rev. B526390View full textAdd to dashboardCite

“…A field-induced Griffiths phase was observed in FeCl 2 , manifesting itself as domainlike AFM correlations in the PM state. 10 Further works claimed the presence of the Griffiths singularity in magnetic semiconductors, 11,12 intermetallics, 13,14 oxides, 2,4,9,12,15,16 and more recently, rare-earth ͑R͒ compounds. [17][18][19] Within rareearth systems, we highlight the R 5 ͑Si x Ge 1−x ͒ 4 family.…”