scholarly journals Osmium Containing Double Perovskite Ba2XOsO6 (X = Mg, Zn, Cd): Important Candidates for Half-Metallic Ferromagnetic and Spintronic Applications

2020 ◽  
Author(s):  
Sajad Ahmad Dar
Keyword(s):  
Double Perovskite ◽  
Half Metallic

scholarly journals Spontaneous atomic ordering and magnetism in epitaxially stabilized double-perovskites

2012 ◽  
Vol 1454 ◽  
pp. 3-13
Author(s):  
Akira Ohtomo ◽  
Suvankar Chakraverty ◽  
Hisanori Mashiko ◽  
Takayoshi Oshima ◽  
Masashi Kawasaki
Keyword(s):  
Magnetic Properties ◽  
Transition Metals ◽  
Double Perovskite ◽  
Perovskite Oxides ◽  
Epitaxial Films ◽  
Atomic Ordering ◽  
Magnetic Ground State ◽  
Half Metallic ◽  
Optical Band Gaps

ABSTRACTWe report on the atomic ordering of B-site transition-metals and magnetic properties in double-perovskite oxides, La2CrFeO6 (LCFO) and La2VMnO6 (LVMO), which have never been reported to exist in ordered forms. These double-perovskite oxides are particularly interesting because of possible ferromagnetism (expected from the Kanamori-Goodenough rule for LCFO) and half-metallic antiferromagnetism (predicted for LVMO). Using pulsed-laser deposition technique with single solid-solution targets, we have prepared epitaxial films in ordered forms. Despite similar ionic characters of constituent transition-metals in each compound, the maximum B-site order attained was surprisingly high, ∼90% for LCFO and ∼80% for LVMO, suggesting a significant role of epitaxial stabilization in the spontaneous ordering process. Magnetization and valence state characterizations revealed that the magnetic ground state of both compounds was coincidently ferrimagnetic with saturation magnetization of ∼2μBper formula unit, unlike those predicted theoretically. In addition, they were found to be insulating with optical band-gaps of 1.6 eV and 0.9 eV for LCFO and LVMO, respectively. Our results present a wide opportunity to explore novel magnetic properties of binary transition-metal perovskites upon epitaxial stabilization of the ordered phase.

scholarly journals Half-Metallic Property Induced by Double Exchange Interaction in the Double Perovskite Bi2BB′O6 (B, B′ = 3d Transitional Metal) via First-Principles Calculations

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1844 ◽  
Author(s):  
Hong-Zong Lin ◽  
Chia-Yang Hu ◽  
Po-Han Lee ◽  
Albert Zhong-Ze Yan ◽  
Wen-Fang Wu ◽  
...  
Keyword(s):  
Exchange Interaction ◽  
Density Functional ◽  
Double Exchange ◽  
Double Perovskite ◽  
Transition Metal Ions ◽  
Spin Interaction ◽  
Metallic Materials ◽  
Generalized Gradient ◽  
Double Exchange Interaction ◽  
Half Metallic

In this paper, we identify three possible candidate series of half-metals (HM) from Bi-based double perovskites Bi2BB′O6 (BB′ = transition metal ions) through calculations utilizing the density functional theory (DFT) and full-structural optimization, in which the generalized gradient approximation (GGA) and the strong correlation effect (GGA + U) are considered. After observing the candidate materials under four types of magnetic states, i.e., ferromagnetic (FM), ferrimagnetic (FiM), antiferromagnetic (AF), and nonmagnetic (NM), we found eight promising candidates for half-metallic materials. Under the GGA scheme, there are three ferromagnetic-half-metal (FM-HM) materials, Bi2CrCoO6, Bi2CrNiO6 and Bi2FeNiO6, and three FiM-HM materials, Bi2FeZnO6, Bi2CrZnO6 and Bi2CoZnO6. With implementation of the Coulomb interaction correction (GGA + U), we find two stable half-metallic materials: Bi2CrNiO6 and Bi2CrZnO6. We determine that the stability of some of these materials are tied to the double exchange interaction, an indirect interaction within the higher powers of localized spin interaction among transition metals via oxygen ions. Found in half-metallic materials, and especially those in the ferromagnetic (FM) state, the double exchange interaction is recognized in the FM-HM materials Bi2CrCoO6 and Bi2FeNiO6.

Magnetisation and Magneto-Resistance Study of Ferromagnetic Metal/Half Metallic Double Perovskite Bi-Layers

2011 ◽  
Vol 700 ◽  
pp. 33-36 ◽  
Author(s):  
Duncan M. McCann ◽  
Grant V. M. Williams ◽  
Adam R. Hyndman ◽  
Jibu Stephen
Keyword(s):  
Thin Film ◽  
Curie Temperature ◽  
Double Perovskite ◽  
Ferromagnetic Metal ◽  
Half Metallic ◽  
Layer Film ◽  
Anomalous Peak ◽  
Magneto Resistance

We observe a large magneto-resistance in very thin Ba2FeMoO6films of ~-12% at 10K, which is not significantly changed when thin NiFe/Ba2FeMoO6bi-layers are made. This suggests that the magneto-resistance in both cases is dominated by inter-grain tunnelling in the Ba2FeMoO6thin film. There is an anomalous peak in the resistance at ~300K in the bi-layer film that can not be easily explained. However, we know that the temperature where this peak occurs is close to the Ba2FeMoO6Curie temperature.

THEORETICAL PREDICTION OF A NEW TYPE OF HALF-METALLIC MATERIALS IN DOUBLE DEROVSKITE Pb2BB′O6 (B, B′ = 3d TRANSITION METAL) VIA FIRST-PRINCIPLE CALCULATIONS

SPIN ◽  
2014 ◽  
Vol 04 (01) ◽  
pp. 1450001
Author(s):  
HUEI-RU FUH ◽  
KE-CHUAN WENG ◽  
YUN-PING LIU ◽  
YIN-KUO WANG
Keyword(s):  
Transition Metal ◽  
Density Functional ◽  
Interaction Mechanism ◽  
Double Exchange ◽  
Double Perovskite ◽  
Generalized Gradient ◽  
Double Exchange Interaction ◽  
Half Metallic ◽  
Metal Atoms ◽  
Transition Metal Atoms

This study investigate the electronic structure of double perovskite Pb 2BB′ O 6 (B, B′ = 3d transition metal atoms) with ab initio calculation. Density functional theory with generalized gradient approximation (GGA) is used to determine the physical proprieties of the materials. Six new half-metallic (HM) materials are found from 45 [Formula: see text] combinations in double perovskite Pb 2BB′ O 6 (of 3d transition metal atoms). There are five ferromagnetic (FM)-HM materials ( Pb 2 ScCrO 6, Pb 2 ScMnO 6, Pb 2 TiVO 6, Pb 2 TiCrO 6 and Pb 2 CrMnO 6) and one ferrimagnetic (FiM)-HM material ( Pb 2 TiFeO 6). The HM property of the materials are attributed to the double-exchange interaction mechanism through the B(t2g)- O (2p)-B′(t2g) π-binding. Besides including the on site Coulomb interaction, GGA+U calculation is also carried out and the HM property is ensured.

Bulrush-Like Double Perovskite: Synthesis, Tunneling Magnetoresistance, and Magnetocaloric Effects

2008 ◽  
Vol 8 (6) ◽  
pp. 2793-2810 ◽  
Author(s):  
W. Zhong ◽  
N. J. Tang ◽  
C. T. Au ◽  
Y. W. Du
Keyword(s):  
Room Temperature ◽  
Recent Observation ◽  
Chemical Properties ◽  
Double Perovskite ◽  
Tunneling Magnetoresistance ◽  
Double Perovskites ◽  
New Approach ◽  
Half Metallic ◽  
Physical And Chemical ◽  
And Chemical Properties

The recent observation of room temperature tunneling magnetoresistance (TMR) in half-metallic A2FeMoO6 (A = Ca, Sr, Ba) double perovskites, and their importance to the emerging field of spintronics has led to considerable effort being dedicated to detailed investigations of the physical and chemical properties of these materials. This article will present an review of our recent investigations covering the synthesis, structures, magnetic and transport properties of "bulrush-like" A2FeMoO6 (A = Sr, Ba). Utilizing the high shape anisotropy as well as the reactivity of A2FeMoO6 to water and a sonochemical technique, we managed to manipulate the properties of grain boundary barriers, and thus put forward a new approach for the enhancement of room temperature TMR. The magnetocaloric effects of A2FeMoO6 double perovskites will also be discussed.

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