Itinerant-electron ferromagnetism inLa1−xSrxCo

Magnetic and transport properties of the spin-state disordered oxide La0.8Sr0.2CoShibasaki1, Terasaki2, Nishibori3 et al. 2011Phys. Rev. B191120View full textAdd to dashboardCite

“…6 Second, hole-doping drives a spin-state crossover to make Co 3+ ions adopt the intermediate or highspin state and causes various magnetic phases. [7][8][9][10][11][12][13][14] A doped Co 4+ ion dresses a cloud of magnetic Co 3+ ions, as observed by neutron scattering. 15 The double-exchange mechanism between the low-spin Co 4+ (t 2g 5 ) and the intermediatespin Co 3+ (e g 1 t 2g 5 ) stabilizes an itinerant ferromagnetic state in La 1−x Sr x CoO 3 and causes spin-glass or clusterglass behavior depending on the Sr concentration.…”

“…In this paper, we show the magnetic and transport properties of polycrystalline samples of La 0. 8 X-ray-diffraction patterns were measured using MoKα radiation (RIGAKU ultraX18 with multilayer mirror) and a Debye-Scherrer camera of radius 286.48 mm with an imaging plate. Oxygen contents of the samples were determined by thermogravimetric H 2 -reduction analysis with reproducibility better than ±0.03 for 3 − δ.…”

Nanomagnetic Droplets and Implications to Orbital Ordering inLa1−xSrxCoO3

“…The excited state can either be the so-called S = 1 intermediate spin (IS) state with a t and is Jahn-Teller active while the S = 2 state is not. The low temperature dependence of χ has been fit equally well with models that consider either spin state [8,10] making this a controversial issue for several decades [7,8,9,11]. Identifying the excited state that leads to the magnetic transition is important as it provides insights to the nature of the Co incident energy E i of 3.27 meV).…”

“…As the gap (∆) between the t 2g and e g orbital states becomes small in the presence of a large trigonal distortion [1,5] aided by strong Co-O hybridization [6], the system can be thermally excited to a magnetic state. Evidence for this is provided by a broad peak in the bulk susceptibility, χ, [1,7,8,9] ∼ 100 K that marks the onset to a paramagnetic state. The excited state can either be the so-called S = 1 intermediate spin (IS) state with a t and is Jahn-Teller active while the S = 2 state is not.…”

Electronic phase separation and other novel phenomena and properties exhibited by mixed-valent rare-earth manganites and related materials

“…Measurements of magnetic relaxation and memory effects have shown that glassy behaviour is common among the cobaltates (Kundu et al 2005a(Kundu et al , 2006. Studies employing local probes such as NMR and Mössbauer spectroscopy have provided direct evidence for different distinct species involving large magnetic/metallic clusters and small nonmagnetic clusters (Bhide et al 1975;Kuhns et al 2003). Thus, the NMR and Mössbauer studies of La (1Kx) Sr x CoO 3 show distinct signals corresponding to FM and PM species.…”