D. Slobinsky

Publications (4)40.09 Total impact

• Article: Fast sweep-rate plastic Faraday force magnetometer with simultaneous sample temperature measurement.

  D Slobinsky, R A Borzi, A P Mackenzie, S A Grigera
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  ABSTRACT: We present a design for a magnetometer capable of operating at temperatures down to 50 mK and magnetic fields up to 15 T with integrated sample temperature measurement. Our design is based on the concept of a Faraday force magnetometer with a load-sensing variable capacitor. A plastic body allows for fast sweep rates and sample temperature measurement, and the possibility of regulating the initial capacitance simplifies the initial bridge balancing. Under moderate gradient fields of ∼1 T/m our prototype performed with a resolution better than 1 × 10(-5) emu. The magnetometer can be operated either in a dc mode, or in an oscillatory mode which allows the determination of the magnetic susceptibility. We present measurements on Dy(2)Ti(2)O(7) and Sr(3)Ru(2)O(7) as an example of its performance.
  The Review of scientific instruments 12/2012; 83(12):125104. · 1.52 Impact Factor
• Source

  Available from: arxiv.com

  Article: Unconventional magnetization processes and thermal runaway in spin-ice Dy2Ti2O7.

  D Slobinsky, C Castelnovo, R A Borzi, A S Gibbs, A P Mackenzie, R Moessner, S A Grigera
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  ABSTRACT: We investigate the nonequilibrium behavior of the spin-ice Dy2Ti2O7 by studying its magnetization as a function of the field sweep rate. Below the enigmatic ''freezing'' temperature T(equil)≈600 mK, we find that even the slowest sweeps fail to yield the equilibrium magnetization curve and instead give an initially much flatter curve. For higher sweep rates, the magnetization develops sharp steps accompanied by similarly sharp peaks in the temperature of the sample. We ascribe the former behavior to the energy barriers encountered in the magnetization process, which proceeds via flipping of spins on filaments traced out by the field-driven motion of the gapped, long-range interacting magnetic monopole excitations. The peaks in temperature result from the released Zeeman energy not being carried away efficiently; the resulting heating triggers a chain reaction.
  Physical Review Letters 12/2010; 105(26):267205. · 7.37 Impact Factor
• Source

  Available from: ArXiv

  Article: Unconventional magnetization processes and thermal runaway in spin-ice Dy$_2$Ti$_2$O$_7$

  D. Slobinsky, C. Castelnovo, R. A. Borzi, A. S. Gibbs, A. P. Mackenzie, R. Moessner, S. A. Grigera
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  ABSTRACT: We investigate the non-equilibrium behavior of the spin-ice material Dy$_2$Ti$_2$O$_7$ by studying its magnetization as a function of the rate at which an external field is swept. At temperatures below the enigmatic "freezing" temperature $T_{\rm equil}\approx600$ mK, we find that even the slowest sweeps fail to yield the equilibrium magnetization curve and instead give a smooth, initially much flatter curve. For higher sweep rates, the magnetization develops sharp steps accompanied by similarly sharp peaks in the temperature of the sample. We ascribe the former behavior to the energy barriers encountered in the magnetization process, which proceeds via flipping of spins on filaments traced out by the field-driven motion of the gapped, long-range interacting magnetic monopole excitations. In contrast, the peaks in temperature result from the released Zeeman energy not being carried away efficiently into the bath, with the resulting heating triggering a chain reaction.
  10/2010;
• Source

  Available from: Jonathan Morris

  Article: Dirac strings and magnetic monopoles in the spin ice Dy2Ti2O7.

  D J P Morris, D A Tennant, S A Grigera, B Klemke, C Castelnovo, R Moessner, C Czternasty, M Meissner, K C Rule, J-U Hoffmann, K Kiefer, S Gerischer, D Slobinsky, R S Perry
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  ABSTRACT: Sources of magnetic fields-magnetic monopoles-have so far proven elusive as elementary particles. Condensed-matter physicists have recently proposed several scenarios of emergent quasiparticles resembling monopoles. A particularly simple proposition pertains to spin ice on the highly frustrated pyrochlore lattice. The spin-ice state is argued to be well described by networks of aligned dipoles resembling solenoidal tubes-classical, and observable, versions of a Dirac string. Where these tubes end, the resulting defects look like magnetic monopoles. We demonstrated, by diffuse neutron scattering, the presence of such strings in the spin ice dysprosium titanate (Dy2Ti2O7). This is achieved by applying a symmetry-breaking magnetic field with which we can manipulate the density and orientation of the strings. In turn, heat capacity is described by a gas of magnetic monopoles interacting via a magnetic Coulomb interaction.
  Science 10/2009; 326(5951):411-4. · 31.20 Impact Factor