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Related papers: Proton-induced magnetic order in carbon: SQUID mea…

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We provide evidence that proton irradiation of energy 2.25 MeV on highly-oriented pyrolytic graphite samples triggers ferro- or ferrimagnetism. Measurements performed with a superconducting quantum interferometer device (SQUID) and magnetic…

Strongly Correlated Electrons · Physics 2007-05-23 P. Esquinazi , D. Spemann , R. Höhne , A. Setzer , K. -H. Han , T. Butz

Medium-energy ion irradiation is a promising technique for inducing magnetism in materials with partially filled d or f electron bands. This approach enables precise control over the density and spatial distribution of irradiation-induced…

Materials Science · Physics 2025-11-24 Ram Kumar , Aditya H. Kelkar , Neeraj Shukla , Paras Poswal , Sheshmani Singh

In this work we have investigated the changes of the magnetic properties of highly oriented pyrolytic graphite samples after irradiation either with $\sim 3 \times 10^{14}$ protons or $ 3.5 \times 10^{13} ... 3.5 \times 10^{14}$ iron ions…

Strongly Correlated Electrons · Physics 2009-11-13 J. Barzola-Quiquia , R. Höhne , M. Rothermel , A. Setzer , P. Esquinazi , V. Heera

We have investigated the variation in the magnetization of highly ordered pyrolytic graphite (HOPG) after neutron irradiation, which introduces defects in the bulk sample and consequently gives rise to a large magnetic signal. We observe…

In this study, the impurity concentration and magnetic response of nine highly oriented pyrolytic graphite (HOPG) samples with different grades and from different providers were determined using ion beam microscopy and SQUID magnetometry.…

Materials Science · Physics 2014-06-23 D. Spemann , P. Esquinazi , A. Setzer , W. Böhlmann

Recently, magnetic order in highly oriented pyrolytic graphite (HOPG) induced by proton broad- and microbeam irradiation was discovered. Theoretical models propose that hydrogen could play a major role in the magnetism mechanism. We…

In this chapter we review the magnetic effects produced by proton irradiation on graphite, disordered carbon and fullerene films. The advantage of proton irradiation is twofold: it enables us to make an impurity analysis simultaneously to…

Materials Science · Physics 2007-05-23 P. Esquinazi , R. Höhne , K. -H. Han , D. Spemann , A. Setzer , M. Diaconu , H. Schmidt , T. Butz

We report the observation of proximity effect in measurements performed on highly oriented pyrolitic graphite (HOPG) samples when electrical current is injected through the superconducting electrodes placed on the sample surface few…

The development of radiation-tolerant materials capable of maintaining structural, electrical, and thermal stability in extreme, radiation-rich environments remains a critical challenge in materials science. In this work, the effects of 60…

Ferromagnetism in carbon-based materials is appealing for both applications and fundamental science purposes because carbon is a light and bio-compatible material that contains only s and p electrons in contrast to traditional ferromagnets…

Materials Science · Physics 2009-10-13 J. Cervenka , M. I. Katsnelson , C. F. J. Flipse

The magnetic properties of disordered graphene and irradiated graphite are systematically studied using a combination of mean-field Hubbard model and first-principles calculations. By considering large-scale disordered models of graphene, I…

Materials Science · Physics 2008-07-17 Oleg V. Yazyev

We report on an extensive investigation to figure out the origin of room-temperature ferromagnetism that is commonly observed by SQUID magnetometry in highly-oriented pyrolytic graphite (HOPG). Electron backscattering and X-ray…

Materials Science · Physics 2012-02-01 M. Sepioni , R. R. Nair , I-Ling Tsai , A. K. Geim , I. V. Grigorieva

A wide variety of resistive and field dependent behaviors have been previously observed in both doped and non-doped Highly Oriented Pyrolytic Graphite (HOPG). We find HOPG samples to vary significantly in their temperature dependent…

Materials Science · Physics 2013-02-07 Nicholas Cornell , M. B. Salamon , A. Zakhidov

We have prepared magnetic graphite samples bombarded by protons at low temperatures and low fluences to attenuate the large thermal annealing produced during irradiation. An overall optimization of sample handling allowed us to find Curie…

Strongly Correlated Electrons · Physics 2009-11-13 J. Barzola-Quiquia , P. Esquinazi , M. Rothermel , D. Spemann , T. Butz , N. García

We report the magnetic response of high purity type IIa single crystal CVD diamond following high energy irradiation by 2.2 MeV proton micro-beams, produced using Nuclear Microprobe techniques. Post-irradiation microanalysis is achieved…

Isolated hydrogen atoms absorbed on graphene are predicted to induce magnetic moments. Here we demonstrate that the adsorption of a single hydrogen atom on graphene induces a magnetic moment characterized by a ~20 meV spin-split state at…

Pressure induced long range antiferromagnetic order is discovered in Yb2Pd2Sn by measuring the electrical resistivity under pressure up to 5.0 GPa. Magnetic ordering is observed above about 1.0 GPa, being the lowest pressure in…

Strongly Correlated Electrons · Physics 2007-06-13 Takaki Muramatsu , Taisuke Kanemasa , Ernst Bauer , Mauro Giiovannini , Tomoko Kagayama , Katsuya Shimizu

The occurrence of scissors modes in crystals that have deformed ions in their cells has been predicted some time ago. The theoretical value of their energy is rather uncertain, however, ranging between 10 and a few tenths of eV, with the…

Materials Science · Physics 2015-05-06 Keisuke Hatada , Kuniko Hayakawa , Fabrizio Palumbo , Augusto Marcelli

We present a study of the magnetoresistance of highly oriented pyrolytic graphite (HOPG) as a function of the sample size. Our results show unequivocally that the magnetoresistance reduces with the sample size even for samples of hundreds…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 J. C. González , M. Muñoz , N. García , J. Barzola-Quiquia , D. Spoddig , K. Schindler , P. Esquinazi

We have studied the magnetization of various, well characterized samples of highly oriented pyrolitic graphite (HOPG), Kish graphite and natural graphite to investigate the recently reported ferromagnetic-like signal and its possible…

Strongly Correlated Electrons · Physics 2009-11-07 P. Esquinazi , A. Setzer , R. Hoehne , C. Semmelhack , Y. Kopelevich , D. Spemann , T. Butz , B. Kohlstrunk , M. Loesche
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