Magnetic properties of La1−xCaxCoO3 single crystals

Magnetic and structural transitions inLa1−xAxCoO3(Kriener1, Braden2, Kierspel3 et al. 2009Phys. Rev. B360350View full textAdd to dashboardCite

“…19,[26][27][28] Compared to the Sr-doping and Ba-doping series, our magnetization data are qualitatively different in the case of A = Ca. Instead of a low magnetic moment M 4K ͑magnetization at 4 K͒ observed for the Sr-doping and Ba-doping series, the Ca-doped samples exhibit clear signatures of ferromagnetic order already for small doping concentrations with M 4K values of the same order of magnitude as the values found for the highly Srdoped and Ba-doped ferromagnetic compounds.…”

“…This suggests that the ferromagnetic order in La 1−x Ca x CoO 3 is rather unconventional as has been proposed recently based on relaxation-time measurements of the dc magnetization, too. 27,48 Indications for a spin-glass state rather than a ferromagnet have also been found in neutron diffraction for the Ca concentration x = 0.05. 49 note the ferromagnetic T c from magnetization data and, in addition, the temperatures T LTM ␣ and T HTM ␣ of the ␣͑T͒ minima are marked by blue stars and green diamonds, respectively.…”

Photoemission band structure of La0.7(Ca, Ce)0.3MnO3 thin films and a La0.9Ca0.1CoO3 crystal

“…Crystalization was performed in oxygen pressure of 1 atm and the sintering temperature was 1250 • C. The observed X-ray diffraction lines were narrow and the space group R3c was evaluated by the Rietveld method. The details of the crystallization and characterisation of the cobaltite crystal are described in [6]. In room temperature the crystal is an antiferromagnetic insulator with the paramagnetic Curie temperature −29 K.…”

“…In the DE model 3d ions should exist in mixed-valent state which can be visualised by writing the formula in the form of La 3+ 1−x Ca 2+ [3][4][5]. A question arises whether the DE mechanism plays also a role in the system with Mn ions being in the Mn 2+ [6]. A number of electron photoemission studies for different mixed-valent manganese perovskites were reported up to now, e.g.…”

Structural, electrical and magnetic properties of perovskites La0.67Ca0.33Mn1−xCoxO3 (0.5⩽x⩽1)

“…This behavior suggests that the Co subsystem has the main role in electrical conduction. The low values of the resistivities in the high-temperature region can be attributed to the disproportionation effect for Co 3+ ions in Co 2+ and Co 4+ [6].…”