scholarly journals Origin of Perovskite Multiferroicity and Magnetoelectric-Multiferroic Effects—The Role of Electronic Spin in Spontaneous Polarization of Crystals

2022 ◽  
Vol 8 (1) ◽  
pp. 9
Author(s):  
Isaac B. Bersuker

In this semi-review paper, we show that the multiferroic properties of perovskite ABO3 crystals with B(dn), n > 0, centers are fully controlled by the influence of the electronic spin on the local dipolar instability that triggers the spontaneous polarization of the crystal. Contrary to the widespread statements, the multiferroicity of these crystals does not emerge due to the addition of unpaired electrons (carrying magnetic moments) to the spontaneously polarizing crystal; the spin states themselves are an important part of the local electronic structure that determines the very possibility of the spontaneous polarization. This conclusion emerges from vibronic theory, in which the ferroelectricity is due to the cooperative interaction of the local dipolar distortions induced by the pseudo-Jahn-Teller effect (PJTE). The latter requires sufficiently strong vibronic coupling between ground and excited electronic states with opposite parity but the same spin multiplicity. The detailed electronic structure of the octahedral [B(dn)O6] center in the molecular orbital presentation shows how this requirement plays into the dependence of the possible perovskite magnetic, ferroelectric, and multiferroic properties on the number of d electrons, provided the criterion of the PJTE is obeyed. Revealed in detail, the role of the electronic spin in all these properties and their combination opens novel possibilities for their manipulation by means of external perturbations and exploration. In particular, it is shown that by employing the well-known spin-crossover phenomenon, a series of novel effects become possible, including magnetic-ferroelectric (multiferroic) crossover with electric-multiferroic, magnetic-ferroelectric, and magneto-electric effects, some of which have already been observed experimentally.

1987 ◽  
Vol 104 ◽  
Author(s):  
G. A. Baraff ◽  
M. Lannoo ◽  
M. Schluter

ABSTRACTThe levels and excitation energies of the weakly interacting AsGa—Asi defect pair have been calculated using the model energy functional introduced by Baraff and Schluter, modified so as to allow Jahn Teller relaxation to distort the Asi away from the symmetry site. The physics underlying this calculation and the results emerging from it are described in this paper. We find that many previously unrelated experimental observations about EL2 are well accounted for by this model. However, there are still some controversial aspects of the fit of the model to the observed properties of EL2 which we cite as requiring further study.


2021 ◽  
Vol 490 ◽  
pp. 229519
Author(s):  
Renier Arabolla Rodríguez ◽  
Nelcy Della Santina Mohallem ◽  
Manuel Avila Santos ◽  
Demetrio A. Sena Costa ◽  
Luciano Andrey Montoro ◽  
...  

2021 ◽  
Vol 23 (12) ◽  
pp. 7418-7425
Author(s):  
Magdalena Laurien ◽  
Himanshu Saini ◽  
Oleg Rubel

We calculate the band alignment of the newly predicted phosphorene-like puckered monolayers with G0W0 according to the electron affinity rule and examine trends in the electronic structure. Our results give guidance for heterojunction design.


2021 ◽  
Vol 867 ◽  
pp. 158794
Author(s):  
P.D. Thang ◽  
N.H. Tiep ◽  
T.A. Ho ◽  
N.D. Co ◽  
N.T.M. Hong ◽  
...  

Author(s):  
Anju Kumari ◽  
Kavita Kumari ◽  
Rezq Naji Aljawfi ◽  
P. A. Alvi ◽  
Saurabh Dalela ◽  
...  

1995 ◽  
Vol 384 ◽  
Author(s):  
Zhi-Qiang Li ◽  
Yuichi Hashi ◽  
Jing-Zhi Yu ◽  
Kaoru Ohno ◽  
Yoshiyuki Kawazoe

ABSTRACTThe electronic structure and magnetic properties of rhodium clusters with sizes of 1 - 43 atoms embedded in the nickel host are studied by the first-principles spin-polarized calculations within the local density functional formalism. Single Rh atom in Ni matrix is found to have magnetic moment of 0.45μB. Rh13 and Rhl 9 clusters in Ni matrix have lower magnetic moments compared with the free ones. The most interesting finding is tha.t Rh43 cluster, which is bulk-like nonmagnetic in vacuum, becomes ferromagnetic when embedded in the nickel host.


2016 ◽  
Vol 18 (45) ◽  
pp. 30946-30953 ◽  
Author(s):  
Damien Magne ◽  
Vincent Mauchamp ◽  
Stéphane Célérier ◽  
Patrick Chartier ◽  
Thierry Cabioc'h

The role of the surface groups in chemical bonding in two dimensional Ti3C2is evidenced at the nano-object level.


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