Reversible and irreversible structural changes in FeO/Ru(0 0 0 1) model catalyst subjected to atomic oxygen

بررسی‌های ساختاری و مغناطیسی نانوذرات‌ پروسکایت LaMn1-xCoxO3 (0/1، 75/0، 5/0، 25/0، 0/0 = x)

In this work, the structural and magnetic properties of LaMn1-xCoxO3 (x = 0.00, 0.25, 0.50, 0.75, 1.00) are investigated. The structural characterization of compounds by X-ray powder diffraction is evidence for a rhombohedral structure (R -3c space group). Much less increase of the unit cell volume suggests that Co enters in lattice as Co+2 for x ≤ 0.5 while much more decrease of the unit cell ...

Adsorption of atomic and molecular oxygen on Cu(1 0 0)

We have studied the initial stages of the oxidation of the Cu(1 0 0) surface using ab initio calculations. Both atomic and molecular oxygen are addressed. We show that subsurface oxygen is not energetically favourable, but gets stabilized by on-surface O. We discuss the adsorption of molecular oxygen using elbow plots, which can be used in order to qualitatively understand the measured sticking...

ساخت نانو بلورک‌های δ-7O3Cu2YBa به روش مکانوشیمیایی و بررسی دمای گذار ترکیبات -7O3Cu2YBa(x-1) + 2 xMnO (02/0 ،015/0 ،01/0 ،005/0 ،0 = x)

In this research, YBa2Cu3O7-d (0 < d < 1) nanocrystalite superconductor was prepared by mechanochemical alloying method. We synthesized YBa2Cu3O7-d via mixing the BaCO3, Y2O3, CuO powders and milling in SPEX 8000 for 5h with weight ratio of ball to powder 10:1 and steel balls of 11mm diameter, followed by heating for 4h at 850 ˚C. The superconductor phase formation process was completed with si...

GCMC Glauber dynamics study for structural transitions in YBCOx (0<x<1), HTc system

We have chosen an Ising ASYNNNI (ASYmmetric Next Nearest Neighbor Interaction)   model under a grand canonical regime to investigate structural phase transition from a high symmetric tetragonal (Tet) to a low symmetric orthorhombic in YBa2Cu3O6+x , 0<x<1,  HTc system. Ordering process for absorbed oxygens from an external gas bath into the basal plane of the layered system is studied by Monte C...

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