The magnetic moment and the order induced by localized defects, like vacancies, interstitials, and/or nonmagnetic (NM) ions, in a NM oxide atomic lattice are discussed. When defect concentration is of or larger than ≈3 at%, at room temperature can appear. Herein, theoretical basic principles needed to understand compute this new phenomenon solids developed detail. In particular, main results density functional theory (DFT) calculations used estimate magnetization X‐ray circular dichroism...

Granular superconductivity at high temperatures in graphite can emerge certain two-dimensional (2D) stacking faults (SFs) between regions with twisted (around the c-axis) or untwisted crystalline Bernal (ABA…) and/or rhombohedral (ABCABCA…) order. One way to observe experimentally such 2D is measure frozen magnetic flux produced by a permanent current loop that remains after removing an external field applied normal SFs. Magnetic force microscopy was used localize and characterize path found...

The electrical, in-plane resistance as a function of temperature $R(T)$ bulk and mesoscopic thin graphite flakes obtained from the same batch was investigated. Samples thicker than $\ensuremath{\sim}30$ nm show metalliclike contribution in range that increases with sample thickness, whereas semiconductinglike behavior observed for thinner samples. dependence all measured samples several others literature can be very well explained between 2 1100 K assuming three contributions parallel:...

Magnetic order at room temperature induced by atomic lattice defects, like vacancies, interstitials, or their pairs, has been observed in a large number of different non-magnetic hosts, such as pure graphite, oxides, and silicon-based materials. High Curie temperatures time-independent magnetic response indicate the extraordinary robustness this new phenomenon solid-state magnetism. In work, we review experimental theoretical results TiO 2 (anatase), whose can be triggered low-energy ion...

We investigated the electric transport properties of single TiO2 nanotubes separated from an anodic titania nanotube array. The temperature dependence resistance measured with conventional four point method all samples show a Mott variable range hopping behavior. results obtained two contacts indicate existence potential barrier between Cr/Au and surfaces, which influence is clearly observable at temperatures <150 K. Impedance spectroscopy in frequency 40 Hz to 1 MHz carried out room...

We present a new method to obtain topological insulator Bi2Se3 thin films with centimeter large lateral length. To produce amorphous films, we have used sequential flash-evaporation at room temperature. Transmission electron microscopy has been verify that the prepared samples are in pure state. During annealing, transform into rhombohedral crystalline structure which was confirmed using X-ray diffraction and Raman spectroscopy. Resistance measurements of show expected Mott variable range...

The temperature and field dependence of the magnetization epitaxial, undoped anatase TiO2 thin films on SrTiO3 substrates was investigated. Low-energy ion irradiation used to modify surface within a few nanometers, yet with high enough energy produce oxygen titanium vacancies. as-prepared film shows ferromagnetism which increases after low-energy ions. An optimal clear magnetic anisotropy observed first irradiation, opposite expected form anisotropy. Taking into account experimental...

Abstract The magnetization of nitrogen-doped single crystalline diamond bulk samples shows unconventional field and temperature hysteresis loops at T $${\boldsymbol{\lesssim }}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>≲</mml:mo> </mml:math> 25 K. results suggest the existence superparamagnetic superconducting regions in with nitrogen concentration &lt;200 ppm. Both phases vanish temperatures above K where show diamagnetic behavior similar to undoped diamond....

In this work we have used focused electron beam induced deposition of cobalt to functionalize atomic force microscopy Akiyama tips for application in magnetic microscopy. The grown a content ≈ Co after exposure ambient air. were characterized using energy dispersive x-ray spectroscopy and scanning order investigate the properties, current loops prepared by lithography. Measurements at room temperature as well carried out coercive field mT tip was estimated applying several external fields...

This work focuses on the generation of ferromagnetism at surface anatase ${\mathrm{TiO}}_{2}$ films by low-energy ion irradiation. Controlled ${\mathrm{Ar}}^{+}$-ion irradiation resulted in a thin $(\ensuremath{\sim}10)$ nm ferromagnetic layer. The intrinsic origin and robustness magnetic order has been characterized x-ray circular dichroism room temperature revealing that Ti band is spin-polarized. These results, together with density functional theory calculations, indicate...

A model identifying defects formation and structural as well chemical changes crucial parameters for a co-catalyst free photocatalytic H 2 evolution activity in epitaxial grown anatase single crystals is presented.

Tunneling atomic force microscopy (TUNA) was used at ambient conditions to measure the current-voltage $(I\text{\ensuremath{-}}V)$ characteristics clean surfaces of highly oriented graphite samples with Bernal and rhombohedral stacking orders. The characteristic curves measured on Bernal-stacked can be understood an ordinary self-consistent semiconductor modeling quantum mechanical tunneling current derivations. We show that absence a voltage region without measurable in...

A detailed magnetoresistance (MR) study of bulk and microflake samples highly oriented pyrolytic graphite in a broad temperature $240\ensuremath{\gtrsim}T\ensuremath{\gtrsim}1\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ magnetic field ${\ensuremath{\mu}}_{0}H\phantom{\rule{0.16em}{0ex}}\ensuremath{\le}62\phantom{\rule{0.16em}{0ex}}\mathrm{T}$ range, reveals the existence three independent phenomena, contributions which are observed at different temperatures fields. The identification phenomena...

In this work we investigated the electrical properties of rapidly quenched amorphous Bi x Sb alloys in temperature range 1.2 K to 345 K. The resistance reveals that for a broad different compositions, including topological insulator (TI), superconducting state phase is present. After crystallization and annealing at an intermediate temperature, found pure with composition corresponding TI, superconductivity persists, but transition shifts lower temperature. highest was those TI's, shift low...

We have investigated the electrical resistance R(T) of ZnO nanowires ≈ 400 nm diameter as a function temperature, between 30 K and 300 K, frequency in range 40 Hz to MHz. The measurements were done on as-prepared after low-energy proton implantation at room temperature. temperature dependence wire, before implantation, can be well described by two processes parallel. One process is fluctuation induced tunneling conductance (FITC) other usual thermally activated process. existence was also...

We report measurements of transmission electron microscopy, the electrical resistivity, magnetoresistance and Hall effect (HE) in amorphous quasicrystalline (QC) phase . The samples are prepared situ at K as thin films phase. After preparation, sample was measured during annealing different temperatures. were performed temperature range 1.2–300 with fields up to ±8 T. Atomic structure information obtained by spectroscopy reveals that icosahedral local atomic order is already present improved...

Granular superconductivity at high temperatures in graphite can emerge certain two-dimensional (2D) stacking faults (SFs) between regions with twisted (around the c-axis) or untwisted crystalline Bernal (ABA...) and/or rhombohedral (ABCABCA...) order. One way to observe experimentally such 2D is measure frozen magnetic flux produced by a permanent current loop that remains after removing an external field applied normal SFs. Magnetic force microscopy was used localize and characterize path...

Placing electrodes at the edges of stacking faults, for example between Bernal and rhombohedral orders as in sketch, observable by transmission electron microscopy a micrometer-size Sri Lankan natural graphite sample, record values change resistance with magnetic field has been found. The magnetoresistance (MR) increases linearly reaches ≈107% B = 21 T. For more details please refer to article Pablo D. Esquinazi co-workers number 1900991.