Structure, magnetization, and resistivity ofLa1−xMxCoO

Abstract

We present an investigation of the influence of structural distortions in charge-carrier doped La1−xMxCoO3 by substituting La 3+ with alkaline earth metals of strongly different ionic sizes, that is M = Ca 2+ , Sr 2+ , and Ba 2+ , respectively. We find that both, the magnetic properties and the resistivity change non-monotonously as a function of the ionic size of M. Doping La1−xMxCoO3 with M = Sr 2+ yields higher transition temperatures to the ferromagnetically ordered states and lower resistivities than doping with either Ca 2+ or Ba 2+ having a smaller or larger ionic size than Sr 2+ , respectively. From this observation we conclude that the different transition temperatures and resistivities of La1−xMxCoO3 for different M (of the same concentration x) do not only depend on the varying chemical pressures. The local disorder due to the different ionic sizes of La 3+ and M 2+ play an important role, too.

Room-temperature ferromagnetism inSr1−xYxCoO3−δKobayashi1, Ishiwata2, Terasaki3 et al. 2005Phys. Rev. B9214780View full textAdd to dashboardCite

“…In fact, the observed ferromagnetic state is quite different from that in the oxygen-deficient samples: T c is remarkably lower, but the magnetization is larger. These features are essentially similar to M (T ) of La 1−x Sr x CoO 3 [6]. These differences clearly reveal that oxygen deficiency is essential to the peculiar room-temperature ferromagnetism.…”

“…Perovskite Co oxides also show very rich physics such as spin-state transition [4,5], ferromagnetism [6], and thermoelectricity [7]. The ferromagnetism in the perovskite Co oxide La 1−x Sr x CoO 3 has been explained in terms of the double-exchange interaction between Co 3+ and Co 4+ in the intermediate spin state.…”

Influence of Al doping in LaCoO3 on structural, electrical and magnetic properties

“…Such charge carrier doping modifies the magnetic ground state as well as renders the system metallic above a particular value of doping concentration (x) [20][21][22][23][24]. But with B site doping of the ABO 3 structure, there has not been such a comprehensive discussion regarding the structural as well as transport properties.…”

Electrical resistivity anomaly in (Pr1−yMy)1−xCaxCoO3 epitaxial films (M=Y, Gd) fabricated by pulsed laser deposition

“…In the La 1−x Sr x CoO 3 system, single crystals and thin films have been fabricated and investigated. [17][18][19] In the epitaxial thin film, the electrical conduction and the spin state change depending on the film thickness and fabrication condition. 19 However, for the (Pr 1−y M y ) 1−x Ca x CoO 3 system with the simultaneous MI and SS transition, only polycrystalline bulk materials have been investigated experimentally in the previous studies and there is no investigations using a single crystal or an epitaxial film because of the difficulty of the fabrication.…”