Magnetic phase separation in double layer ruthenates Ca3(Ru1−xTix)2O7

Abstract

A phase transition from metallic AFM-b antiferromagnetic state to Mott insulating G-type antiferromagnetic (G-AFM) state was found in Ca3(Ru1−xTix)2O7 at about x = 0.03 in our previous work. In the present, we focused on the study of the magnetic transition near the critical composition through detailed magnetization measurements. There is no intermediate magnetic phases between the AFM-b and G-AFM states, which is in contrasted to manganites where a similar magnetic phase transition takes place through the presence of several intermediate magnetic phases. The AFM-b-to-G-AFM transition in Ca3(Ru1−xTix)2O7 happens through a phase separation process in the 2–5% Ti range, whereas similar magnetic transitions in manganites are tuned by 50–70% chemical substitutions. We discussed the possible origin of such an unusual magnetic transition and compared with that in manganites.

In Situ Control of Diamagnetism by Electric Current in Ca3(Ru1−xTix

“…With further increase of the magnetic field, the magnetization slope changes to positive for µ 0 H > 2.5 T, after which also M becomes positive. At 6.5 T the magnetization suddenly jumps by a factor of 7, indicating the occurrence of a metamagnetic transition, where the AFM-b ordered phase changes into a field-induced ferromagnetic state [33,34]. As an effect of this transition, the resistance exhibits a flattening around 6.5 T (Fig.…”

Electronic and Magnetic Properties of Cation Ordered Sr2Mn2.23Cr0.77As2O2

“…indicating that the magnetic transitions influences the distortion of the tetrahedra within the M'2As2 2-layer at 150 K, resulting in a subtle change in the a and c cell parameters. Magnetic phase separation has been well studied in transition metal oxides such as the perovskite La1−xCaxMnO3 26 and more recently in the ruthenate Ca3(Ru1-xTix)2O7 27 and the ferrite CaFe3O5 28 .…”

“…Magnetic phase separation has been well studied in transition metal oxides such as the perovskite La 1– x Ca x MnO 3 and more recently in the ruthenate Ca 3 (Ru 1– x Ti x ) 2 O 7 and the ferrite CaFe 3 O 5 . Electronic phase separation into antiferromagnetic and superconducting/normal-state regions has been observed in Fe pnictides such as Ba 1– x K x Fe 2 As 2 .…”

Magnetic Phase Separation in the Oxypnictide Sr2Cr1.85Mn1.15As2O2

“…Examples include the colossal magnetoresistant manganite perovskites where chemical doping on the Mn site results in competition between a charge/orbital-ordered antiferromagnetic phase and a ferromagnetic metallic phase 32 and Ca 3 (Ru 1−x Ti x ) 2 O 7 where two competing antiferromagnetic phases are observed in a narrow doping range (x = 0.02−0.05). 33 Such magnetic phase separation has not been previously observed in Sr 2 M 3 As 2 O 2 phases (M = Cr, Mn). It has been established that the intraplanar coupling constant is several orders of magnitude greater than the interlayer coupling constant, due to the long interlayer distance in these compounds.…”

“…Magnetic phase separation occurs when there is competition between magnetic ground states. Examples include the colossal magnetoresistant manganite perovskites where chemical doping on the Mn site results in competition between a charge/orbital-ordered antiferromagnetic phase and a ferromagnetic metallic phase and Ca 3 (Ru 1– x Ti x ) 2 O 7 where two competing antiferromagnetic phases are observed in a narrow doping range ( x = 0.02–0.05) . Such magnetic phase separation has not been previously observed in Sr 2 M 3 As 2 O 2 phases (M = Cr, Mn).…”