Electronic, structural and magnetic phase diagram of Sm1-xSrxMnO3 manganites

Djabrailov²,

2019

Sci Rep

There are the chains of transition-metal cations alternating with the anions of oxygen in ternary transition-metal oxides. When a p-orbital of the oxygen connects the half-filled and empty d-orbitals of adjacent transition-metal cations, double-exchange ferromagnetism takes place. Although double exchange has been well explored, the nature of novel criticality, induced by it, is yet not uncovered. We explored the magnetic-field scaling in the heat capacity of a Sm0.55Sr0.45MnO3 manganite, one of the best ternary transition-metal oxides as it is completely ferromagnetic, and found novel criticality - unordinary critical exponents which are the consequence of coherence of Coulomb lattice distortion and ferromagnetism. The coherence is caused by the trinity of the mass, the charge and the spin of an electron. When the d and p orbitals overlaps, it quickly walks from one site to the another due its lightest mass. And due to its electric charge, it equalizes the valences of the transition-metal cations in the chains and so diminishes the Coulomb lattice distortion. At last, its spin forces magnetic moments of transition-metal cations to ferromagnetically arrange. The disappearance of Coulomb distortions widens the overlap and lowers the elastic lattice energy, so that not only the spin of an electron, but also its electric charge strengthens ferromagnetism. That nonlinear effect strengthens the critical behaviour and critical exponents come off any known universality classes. Thus, the symbiotic coherence of annihilating Coulomb distortions and arising ferromagnetism is a reason of the novel criticality.

Section: Methodsmentioning

confidence: 99%

Nature of novel criticality in ternary transition-metal oxides

Djabrailov²,

2019

Sci Rep

“…Although many papers report the magnetic and electronic properties of R 1-x A x MnO 3 18–20 , they mostly report on bulks and much less often on films 21–24 . For future applications of manganite films, a detailed characterization of the film properties is required.…”

Section: Introductionmentioning

confidence: 99%

“…To our knowledge, this article is the first report discussing the strain effect on the electronic structure of SSMO thin film. The mixed phase of ferromagnetic and antiferromagnetic states makes the properties of SSMO more sensitive to changes in crystal structure 20 . The significant difference of physical properties between bulk and thin film has important implications for device design.…”

Section: Introductionmentioning

confidence: 99%

Atomic replacement effects on the band structure of doped perovskite thin films

Cheng

Chuang

et al. 2019

Sci Rep

The potential applications of perovskite manganite R 1-x A x MnO 3 (R = rare earth element; A = Sr, Ca) thin films have been continuously explored due to their multi-functional properties. In particular, the optimally hole-doped La 0.67 Ca 0.33 MnO 3 thin film demonstrates a colossal magneto-resistance that is beneficial to the performance of spintronic devices. To understand the effect of R and A ions on the material properties, we systematically measure the resistivity, magnetization, and electronic energy states for three optimally hole-doped R 0.67 A 0.33 MnO 3 thin films with R = La, Sm and A = Sr, Ca. Various energy parameters are derived based on the X-ray absorption and X-ray photoelectron spectra, including the band gap, the charge frustration energy and the magnetic exchange energy. It is interesting to find that the replacement of La with Sm is more effective than that of Sr with Ca in terms of tuning the electrical property, the Curie temperature, and the band gap. The strain-induced reduction of the O 2 p - Mn 3 d hybridization and the interplay of R/A site disorder and strain effect are discussed. The results of this study provide useful information for the band design of perovskite oxide films.

Journal of Applied Physics

“…[15][16][17][18] In case of Sm 1=2 Ca 1=2Àx Sr x MnO 3 , the end composition at x ¼ 1/2 is already recognized as an interesting system where FM, CO/OO, and A-type AFM states compete with each other. [19][20][21][22][23][24][25] The other end member at x ¼ 0 is rather less studied where a robust CO has been reported with high T CO ($275 K). [26][27][28] In the current investigation, we are motivated to explore the structural, magnetic, and transport properties at the intermediate doping in Sm 1=2 Ca 1=2Àx Sr x MnO 3 (0 < x < 1=2).…”

Section: Introductionmentioning

confidence: 99%

A-site disorder driven sharp field-induced transition and collapse of charge ordering in Sm1/2Ca1/2-xSrxMnO3

Sabyasachi

Karmakar

Majumdar

et al. 2012

Effect of fast neutron irradiation induced defects on the metamagnetic transition In Ce(Fe0.96Ru0.04)2 J. Appl. Phys. 112, 063922 (2012) Cross-plane electronic and thermal transport properties of p-type La0.67Sr0.33MnO3/LaMnO3 perovskite oxide metal/semiconductor superlattices J. Appl. Phys. 112, 063714 (2012) Experimental evidences of the conservation of the S=1 moment in La2RuO5 determined by perturbed angular correlations J. Appl. Phys. 112, 063915 (2012) Effect of thermal cycle on the interfacial antiferromagnetic spin configuration and exchange bias in Ni-Mn-Sb alloy AIP Advances 2, 032181 (2012) Study of ferromagnetic transition in Pd nanometer-scale constrictions using a mechanically controllable break junction techniqueOur study on Sm 1=2 Ca 1=2Àx Sr x MnO 3 (x ¼ 0, 1/6, 1/3, and 1/2) system shows an unusual consequence in magnetic field-induced transition to ferromagnetic metallic state and collapse of charge ordering in the intermediate compositions. Interestingly, the transition is sharp or step-like at low temperature that is observed at much lower field ($75 kOe) for intermediate compositions than the end compositions (not visible up to 100 kOe). The atomic-scale local inhomogeneity/ distortion arising from ionic mismatch due to doping is supposed to be critical behind this field-induced transition. The charge ordering temperature observed from magnetization and magnetoresistance studies decreases with increasing x which is consistent with the results for R 1=2 A 1=2 MnO 3 (R ¼ La À Sm, A ¼ Ca, Sr) family. V C 2012 American Institute of Physics.