Jeremy Carlo - Profile on Academia.edu (original) (raw)

Papers by Jeremy Carlo

$Research paper thumbnail of Synthesis, structure, and magnetic properties of the two-dimensional quantum antiferromagnets (CuBr) A_ {2} B_ {3} O_ {10}(A= Ca, Sr, Ba, Pb; B= Nb, Ta) with the 1/3 …$

Physical Review B, Jan 1, 2008

A 1/3 magnetization plateau was recently observed in the layered perovskite ͑CuBr͒Sr 2 Nb 3 O 10 ... more A 1/3 magnetization plateau was recently observed in the layered perovskite ͑CuBr͒Sr 2 Nb 3 O 10 with S =1/ 2 CuBr layers. In order to control the cell size and thus exchange parameters, we have prepared an isostructural series of ͑CuBr͒A 2 B 3 O 10 ͑A = Ca, Sr, Ba, Pb; B =Nb, Ta͒ and investigated the magnetic properties. We found that the stability of the 1/3 magnetization plateau is systematically tunable by the lattice parameter a. A substantial role played by the superexchange pathway via BO 6 -BO 6 in the magnetic properties is suggested in addition to that via Br. Specific heat and muon spin relaxation measurements show that the appearance of the plateau phase is accompanied by successive phase transitions in low fields-the first one is possibly a structural transition and the second one is a magnetic transition. Frustration may induce the structural distortion and stabilize the 1/3 plateau phase.

$Research paper thumbnail of Superconducting state coexisting with a phase-separated static magnetic order in (Ba, K) Fe_ {2} As_ {2},(Sr, Na) Fe_ {2} As_ {2}, and CaFe_ {2} As_ {2}$

Physical Review B, Jan 1, 2009

By muon spin-relaxation measurements on single-crystal specimens, we show that superconductivity ... more By muon spin-relaxation measurements on single-crystal specimens, we show that superconductivity in the AFe 2 As 2 ͑A =Ca,Ba,Sr͒ systems, in both the cases of composition and pressure tunings, coexists with a strong static magnetic order in a partial volume fraction. The superfluid response from the remaining paramagnetic volume fraction of ͑Ba 0.5 K 0.5 ͒Fe 2 As 2 exhibits a nearly linear variation in T at low temperatures, suggesting an anisotropic energy gap with line nodes and/or multigap effects.

Phase separation and suppression of critical dynamics at quantum phase transitions of MnSi and (Sr1− xCax) RuO3

Nature Physics, Jan 1, 2006

$Research paper thumbnail of Absence of Broken Time-Reversal Symmetry in the Pseudogap State of the High Temperature La_ {2-x} Sr_ {x} CuO_ {4} Superconductor from Muon-Spin-Relaxation …$

Physical review letters, Jan 1, 2008

Absence of broken time-reversal symmetry in the pseudogap state of the high temperature La 2−x Sr... more Absence of broken time-reversal symmetry in the pseudogap state of the high temperature La 2−x Sr x CuO 4 superconductor from muon-spin-relaxation measurements

Static magnetic order and superfluid density of RFeAs (O, F)(R= La, Nd, Ce) and LaFePO studied by muon spin relaxation: Unusual similarities with the behavior of …

Physical Review Letters, Jan 1, 2009

Muon spin relaxation measurements in iron-oxypnictide systems have revealed: (1) commensurate lon... more Muon spin relaxation measurements in iron-oxypnictide systems have revealed: (1) commensurate long-range order in undoped LaFeAsO; (2) a Bessel function line shape in LaFeAs(O0.97F0.03) which indicates possible incommensurate or stripe magnetism; (3) anomalous weak magnetism existing in superconducting LaFePO, CeFeAs(O0.084F0.16), and NdFeAs(O0.88F0.12) but absent in superconducting LaFeAs(O0.92F0.08); and (4) scaling of the superfluid density with T_{c} in the Ce-, La-, and Nd-FeAs superconductors following a nearly linear relationship found in cuprates.

$Research paper thumbnail of Muon spin rotation measurement of the magnetic field penetration depth in Ba (Fe_ {0.926} Co_ {0.074}) _ {2} As_ {2}: Evidence for multiple superconducting gaps$

Muon spin rotation measurement of the magnetic field penetration depth in Ba (Fe_ {0.926} Co_ {0.074}) _ {2} As_ {2}: Evidence for multiple superconducting gaps

Physical Review B, Jan 1, 2009

$Research paper thumbnail of Superconducting state coexisting with a phase-separated static magnetic order in (Ba, K) Fe_ {2} As_ {2},(Sr, Na) Fe_ {2} As_ {2}, and CaFe_ {2} As_ {2}$

Physical Review B, Jan 1, 2009

Phase separation and suppression of critical dynamics at quantum phase transitions of MnSi and (Sr1− xCax) RuO3

Nature Physics, Jan 1, 2006

$Research paper thumbnail of Muon-spin-relaxation studies of magnetic order and superfluid density in antiferromagnetic NdFeAsO, BaFe_ {2} As_ {2}, and superconducting Ba_ {1− x} K_ {x} Fe_ { …$

Physical Review B, Jan 1, 2008

Zero-field (ZF) muon spin relaxation (µSR) measurements have revealed static commensurate magneti... more Zero-field (ZF) muon spin relaxation (µSR) measurements have revealed static commensurate magnetic order of Fe moments in NdOFeAs below TN ∼ 135 K, with the ordered moment size nearly equal to that in LaOFeAs, and confirmed similar behavior in BaFe2As2. In single crystals of superconducting (Ba0.55K0.45)Fe2As2, µSR spectra indicate static magnetism with incommensurate or short-ranged spin structure in ∼ 70 % of volume below TN ∼ 80 K, coexisting with remaining volume which exhibits superfluid-response consistent with nodeless gap below Tc ∼ 30 K. PACS numbers: 74.90.+n 74.25.Nf 75.25.+z 76.75.+i The discovery of the iron oxypnictide superconductor La(O,F)FeAs (T c ∼ 26K) [1] has triggered an unprecedented burst of quality research. Notable progress includes syntheses of materials with higher T c 's [2, 3, 4] containing different Rare Earth (RE) elements, hole doping [5], reduced oxygen [6]

$Research paper thumbnail of Possible Bose-Einstein condensate of magnons in single-crystalline Pb_ {2} V_ {3} O_ {9}$

Physical Review B, Jan 1, 2010

We report the growth and the characterization of single crystals of the S =1/ 2 spin-dimer compou... more We report the growth and the characterization of single crystals of the S =1/ 2 spin-dimer compound Pb 2 V 3 O 9 . Magnetic-susceptibility, torque magnetometry, heat-capacity, and muon-spin-relaxation measurements provide evidence for a field-induced Bose-Einstein condensate of magnons in this system. At low temperatures, the field-dependent phase boundary between the dimerized and the condensed state is well described by the expression T Ã ϰ ͑H − H c1 ͒ 1/ , with = ͑2.00Ϯ 0.04͒.

$Research paper thumbnail of Muon spin relaxation studies of the frustrated quasi-two-dimensional square-lattice spin system Cu (Cl, Br) La (Nb, Ta) _ {2} O_ {7}: Evolution from spin-gap to …$

Physical Review B, Jan 1, 2009

µSR studies of the frustrated quasi-2d square-lattice spin system Cu(Cl,Br)La(Nb,Ta) 2 O 7 : evol... more µSR studies of the frustrated quasi-2d square-lattice spin system Cu(Cl,Br)La(Nb,Ta) 2 O 7 : evolution from spin-gap to antiferromagnetic state

The Magnetic Phase Diagrams of (ca, sr) 2 (ru, ti) o4 and Iron Pnictide Systems Revealed by Muon Spin Relaxation

UMI. ProQuest® Dissertations & Theses The world's most comprehensive collection of disse... more UMI. ProQuest® Dissertations & Theses The world's most comprehensive collection of dissertations and theses. Learn more... ProQuest. The magnetic phase diagrams of (Ca,Sr)2(Ru,Ti)O 4 and iron pnictide systems revealed ...

A Comparison of Local and Long-Range Structure in Bulk CMR Perovskite La_0. 6Y_0. 07Ca_0. 33MnO_3

APS Meeting Abstracts, Jan 1, 2001

Abstract An exploration of correlations between local and long-range periodic structure in a colo... more Abstract An exploration of correlations between local and long-range periodic structure in a colossal magnetoresistance (CMR) manganite bulk specimen has been carried out. High-quality polycrystalline samples of CMR perovskite La_0. 6Y_0. 07Ca_0. 33MnO 3 (LYCMO) have been prepared by solid-state synthesis of precursor oxides and carbonates. High-resolution synchotron x-ray diffraction (XRD) data was collected and Rietveld refinement of long-range periodic structure was performed. Local structural characterization about Mn, Y ...

Magnetic Excitations from the Exotic Ground State of the Quantum FCC Antiferromagnet Ba2YMoO6

Arxiv preprint arXiv: …, Jan 1, 2011

The magnetic phase diagrams of (calcium, strontium)(ruthenium, titanium) oxide and iron pnictide systems revealed by muon spin relaxation

Abstract This thesis comprises two projects exploring the relationships between superconductivity... more Abstract This thesis comprises two projects exploring the relationships between superconductivity (SC) and magnetism:(1) a comprehensive muon spin relaxation and susceptibility study of the ruthenate systems (Ca, Sr) 2RuO 4 and Sr2 (Ru, Ti) O4, and (2) a muon study of the iron pnictide systems R (O, F) FePn,(R= La or a lanthanide, Pn= P or As). While&amp;amp;quot; conventional&amp;amp;quot; SCs are well understood via the BCS theory of electron pairing via phonon interactions, in&amp;amp;quot; unconventional&amp;amp;quot; SCs this model is inadequate and a ...

Physical Review B, Jan 1, 2003

The pressure dependence of the resistivity and structure of La 0.60 Y 0.07 Ca 0.33 MnO 3 has been... more The pressure dependence of the resistivity and structure of La 0.60 Y 0.07 Ca 0.33 MnO 3 has been explored in the pressure range from 1 atm to ϳ7 GPa. The metal to insulator transition temperature (T MI ) was found to reach a maximum and the resistivity achieves a minimum at ϳ3.8 GPa. Beyond this pressure, T MI is reduced with a concomitant increase in the resistivity. Structural measurements at room temperature show that at low pressure ͑below 2 GPa͒ the Mn-O bond lengths are compressed. Between ϳ2 and ϳ4 GPa, a pressure-induced enhancement of the Jahn-Teller ͑JT͒ distortion occurs in parallel with an increase in Mn-O1-Mn bond angle to ϳ180°. Above ϳ4 GPa, the Mn-O1-Mn bond angle is reduced, while the JT distortion appears to remain unchanged. The resistivity above T MI is well modeled by variable range hopping. The pressure dependence of the localization length follows the behavior of T MI .

$Research paper thumbnail of Synthesis, structure, and magnetic properties of the two-dimensional quantum antiferromagnets (CuBr) A_ {2} B_ {3} O_ {10}(A= Ca, Sr, Ba, Pb; B= Nb, Ta) with the 1/3 …$

Physical Review B, Jan 1, 2008

$Research paper thumbnail of Superconducting state coexisting with a phase-separated static magnetic order in (Ba, K) Fe_ {2} As_ {2},(Sr, Na) Fe_ {2} As_ {2}, and CaFe_ {2} As_ {2}$

Physical Review B, Jan 1, 2009

Phase separation and suppression of critical dynamics at quantum phase transitions of MnSi and (Sr1− xCax) RuO3

Nature Physics, Jan 1, 2006

$Research paper thumbnail of Absence of Broken Time-Reversal Symmetry in the Pseudogap State of the High Temperature La_ {2-x} Sr_ {x} CuO_ {4} Superconductor from Muon-Spin-Relaxation …$

Physical review letters, Jan 1, 2008

Static magnetic order and superfluid density of RFeAs (O, F)(R= La, Nd, Ce) and LaFePO studied by muon spin relaxation: Unusual similarities with the behavior of …

Physical Review Letters, Jan 1, 2009

$Research paper thumbnail of Muon spin rotation measurement of the magnetic field penetration depth in Ba (Fe_ {0.926} Co_ {0.074}) _ {2} As_ {2}: Evidence for multiple superconducting gaps$

Muon spin rotation measurement of the magnetic field penetration depth in Ba (Fe_ {0.926} Co_ {0.074}) _ {2} As_ {2}: Evidence for multiple superconducting gaps

Physical Review B, Jan 1, 2009

$Research paper thumbnail of Superconducting state coexisting with a phase-separated static magnetic order in (Ba, K) Fe_ {2} As_ {2},(Sr, Na) Fe_ {2} As_ {2}, and CaFe_ {2} As_ {2}$

Physical Review B, Jan 1, 2009

Phase separation and suppression of critical dynamics at quantum phase transitions of MnSi and (Sr1− xCax) RuO3

Nature Physics, Jan 1, 2006

$Research paper thumbnail of Muon-spin-relaxation studies of magnetic order and superfluid density in antiferromagnetic NdFeAsO, BaFe_ {2} As_ {2}, and superconducting Ba_ {1− x} K_ {x} Fe_ { …$

Physical Review B, Jan 1, 2008

$Research paper thumbnail of Possible Bose-Einstein condensate of magnons in single-crystalline Pb_ {2} V_ {3} O_ {9}$

Physical Review B, Jan 1, 2010

$Research paper thumbnail of Muon spin relaxation studies of the frustrated quasi-two-dimensional square-lattice spin system Cu (Cl, Br) La (Nb, Ta) _ {2} O_ {7}: Evolution from spin-gap to …$

Physical Review B, Jan 1, 2009

The Magnetic Phase Diagrams of (ca, sr) 2 (ru, ti) o4 and Iron Pnictide Systems Revealed by Muon Spin Relaxation

A Comparison of Local and Long-Range Structure in Bulk CMR Perovskite La_0. 6Y_0. 07Ca_0. 33MnO_3

APS Meeting Abstracts, Jan 1, 2001

Magnetic Excitations from the Exotic Ground State of the Quantum FCC Antiferromagnet Ba2YMoO6

Arxiv preprint arXiv: …, Jan 1, 2011

The magnetic phase diagrams of (calcium, strontium)(ruthenium, titanium) oxide and iron pnictide systems revealed by muon spin relaxation

Physical Review B, Jan 1, 2003