Priya Gopal

Transition metal-doped TiO2 and ZnO—present status of the field

There has been considerable recent interest in the design of diluted magnetic semiconductors, with a particular focus on the exploration of different semiconductor hosts. Among these, the oxide-based diluted magnetic semiconductors are attracting increasing attention, following reports of room temperature ferromagnetism in anatase TiO2 and wurtzite ZnO doped with a range of transition metal ions. In this review we summarize the current status of oxide-based diluted magnetic semiconductors, and discuss the influence of growth method, substrate choice, and temperature on the microstructure and subsequent magnetic properties of thin films. We outline the experimental conditions that promote large magnetization and high ferromagnetic Curie temperature. Finally, we review the proposed mechanisms for the experimentally observed ferromagnetism and compare the predictions to the range of available data.

Magnetic interactions in transition-metal-doped ZnO: An ab initio study

We calculate the nature of magnetic interactions in transition-metal doped ZnO using the local spin density approximation and LSDA+\textit{U} method of density functional theory. We investigate the following four cases: (i) single transition metal ion types (Cr, Mn, Fe, Co, Ni and Cu) substituted at Zn sites, (ii) substitutional magnetic transition metal ions combined with additional Cu and Li dopants, (iii) substitutional magnetic transition metal ions combined with oxygen vacancies and (iv) pairs of magnetic ion types (Co and Fe, Co and Mn, etc.). Extensive convergence tests indicate that the calculated magnetic ground state is unusually sensitive to the k-point mesh and energy cut-off, the details of the geometry optimizations and the choice of the exchange-correlation functional. We find that ferromagnetic coupling is sometimes favorable for single type substitutional transition metal ions within the local spin density approximation. However, the nature of magnetic interactions changes when correlations on the transition-metal ion are treated within the more realistic LSDA + \textit{U} method, often disfavoring the ferromagnetic state. The magnetic configuration is sensitive to the detailed arrangement of the ions and the amount of lattice relaxation, except in the case of oxygen vacancies when an antiferromagnetic state is always favored.

Improved predictions of the physical properties of Zn- and Cd-based wide band-gap semiconductors: a validation of the ACBN0 functional

We study the physical properties of Zn

First-principles study of wurtzite-structure MnO

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Improved electronic structure and magnetic exchange interactions in transition metal oxides

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Polarization, piezoelectric constants, and elastic constants of ZnO, MgO, and CdO

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First-principles study of self- and solute diffusion mechanisms inγ′-Ni3Al

=O, S, Se, Te) and Cd

AFLOWπ: A minimalist approach to high-throughput ab initio calculations including the generation of tight-binding hamiltonians

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The AFLOW Fleet for Materials Discovery

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Systematic Band Gap Tuning of BaSnO3 via Chemical Substitutions: The Role of Clustering in Mixed-Valence Perovskites

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