Kida, T., Fenner, L., Wills, A. S., Terasaki, I., Hagiwara, M.
We have investigated magnetic and transport properties of the {\it kagom\'{e}-bilayer} ferromagnet Fe$_{3}$Sn$_{2}$. A soft ferromagnetism and a large anomalous Hall effect are observed. The...
Spherical neutron polarimetry study of hysteresis in multiferroic MnWO4 (2009)
Poole, A, Wills, A S, Brown, P J
The electric-field dependence of the magnetic structure of multiferroic MnWO4 has been investigated using spherical neutron polarimetry as a function of temperature. The application of an electric...
Low temperature magnetic structure of the quasi 1-dimensional magnet Ni2SiO4 (2009)
Colman, R H, Fennell, T, Ritter, C, Lau, G, Cava, R J, Wills, A S
Ni2SiO4, Liebenbergite, is an example of a quasi-one-dimensional magnet made up of frustrated corner sharing triangles of Ni2+ (S = 1) ions that propagate parallel to the b axis. Ni2SiO4 is...
Wills, A. S., Perring, T. G., Raymond, S., Fak, B., Telling, M.
The frustrated magnet clinoatacamite, $\gamma$-Cu$_2$(OH)$_3$Cl, is attracting a lot of interest after suggestions that at low temperature it forms an exotic quantum state termed a Valence Bond Solid...
Zero-point entropy of the spinel spin glasses CuGa_2O_4 and CuAl_2O_4 (2009)
Fenner, L A, Wills, A S, Bramwell, S T, Dahlberg, M, Schiffer, P
The zero-point entropy of a spin glass is a difficult property to experimentally determine and interpret. Spin glass theory provides various predictions, including unphysical ones, for the value of...
A considerable challenge is faced by researchers wishing to identify the propagation vector(s) associated with a magnetic structure or a lattice distortion from powder diffraction data, due to the...
Toward Perfection: Kapellasite, Cu3Zn(OH)6Cl2, a New Model S = 1/2 Kagome Antiferromagnet (2008)
Colman, R. H., Ritter, C., Wills, A. S.
The search for the resonating valence bond (RVB) state continues to underpin many areas of condensed matter research. The RVB is made from the dimerisation of spins on different sites into...
Field induced magnetic order in the frustrated magnet Gadolinium Gallium Garnet (2008)
Petrenko, O. A., Balakrishnan, G., Paul, D. McK, Yethiraj, M., McIntyre, G. J., Wills, A. S.
Gd3Ga5O12, (GGG), has an extraordinary magnetic phase diagram, where no long range order is found down to 25 mK despite \Theta_CW \approx 2 K. However, long range order is induced by an applied field...
Poole, A., Wills, A.S., Lelievre-Berna, E.
Er2Ti2O7 has been proposed as a realization of the XY \langle 111\rangle pyrochlore antiferromagnet with dipolar interactions, where the spins of Er3+ lie perpendicular to the \langle 111\rangle...
The jarosite family of minerals contain antiferromagnetically coupled Fe3+ ions that make up the kagome network. This geometric arrangement of the Fe3+ ions causes magnetic frustration that results...
Aging in a topological spin glass (2006)
Wills, A.S., Dupuis, V., Vincent, E., Hammann, J., Calemczuk, R.
Using a combination of static and time dependent magnetic susceptibility measurements we have examined the nonconventional spin glass phase of the 2-dimensional kagomé antiferromagnet...
The origin of the spin glass transition in a model geometrically frustrated magnet (2006)
Highly frustrated systems have macroscopically degenerate ground states that lead to novel properties. In magnetism its consequences underpin exotic and technologically important effects, such as,...
Magnetic ordering in Gd2Sn2O7: the archetypal Heisenberg pyrochlore antiferromagnet (2006)
Wills, A. S., Zhitomirsky, M. E., Canals, B., Sanchez, J. P., Bonville, P., De Reotier, P. Dalmas, ...
Low-temperature powder neutron diffraction measurements are performed in the ordered magnetic state of the pyrochlore antiferromagnet Gd2Sn2O7. Symmetry analysis of the diffraction data indicates...
Magnetic ordering in Gd2Sn2O7 the archetypal Heisenberg pyrochlore antiferromagnet (2006)
Wills, A.S., Zhitomirsky, M.E., Canals, B., Sanchez, J.P., Bonville, P., De Reotier, P.D., ...
Low-temperature powder neutron diffraction measurements are performed in the ordered magnetic state of the pyrochlore antiferromagnet Gd2Sn2O7. Symmetry analysis of the diffraction data indicates...
Aging and memory properties of topologically frustrated magnets (2005)
Dupuis, V., Vincent, E., Hammann, J., Greedan, J. E., Wills, A. S.
The model 2d kagome system (H3O)Fe3(SO4)2(OH)6 and the 3d pyrochlore Y2Mo2O7 are two well characterized examples of low-disordered frustrated antiferromagnets which rather then condensing into spin...
Conventional and unconventional orderings in the jarosites (2005)
The jarosites make up the most studied family of {\\it kagom\\\'e} antiferromagnets. The flexibility of the structure to substitution of the A and B ions allows a wide range of compositions to be...
Group Theory techniques can aid greatly the determination of magnetic structures. The integration of their calculations into new and existing refinement programs is an ongoing development that will...
Aging in a topological spin glass (2005)
Wills, A. S., Dupuis, V., Vincent, E., Hammann, J., Calemczuk, R.
We have examined the nonconventional spin glass phase of the 2-dimensional kagome antiferromagnet (H_3 O) Fe_3 (SO_4)_2 (OH)_6 by means of ac and dc magnetic measurements. The frequency dependence of...
Magnetic ordering in the spin-ice candidate Ho{2}Ru{2}O{7} (2004)
Wieble, C.R., Gardner, J.S., Luke, G.M., Wills, A.S., Gaulin, D.B., ...
Neutron scattering measurements on the spin-ice candidate material Ho2Ru2O7 have revealed two magnetic transitions at T∼95 and ∼1.4 K to long-range ordered states involving the Ru and Ho...
Phase transitions, partial disorder and multi-k structures in Gd2Ti2O7 (2004)
Stewart, J.R., Ehlers, G., Wills, A.S., Bramwell, S.T., Gardner, J.S.
The geometrically frustrated antiferromagnet Gd2Ti2O7 exhibits magnetic behaviour of such complexity that it poses a challenge to both experiment and theory. Magnetic ordering commences at TN = 1.1 K...
Magnetic Ordering in the Spin-Ice Candidate Ho$_2$Ru$_2$O$_7$ (2004)
Wiebe, C. R., Gardner, J. S., Luke, G. M., Wills, A. S., Gaulin, B. D., ...
Neutron scattering measurements on the spin-ice candidate material Ho$_2$Ru$_2$O$_7$ have revealed two magnetic transitions at T $\sim$ 95 K and T $\sim$ 1.4 K to long-range ordered states involving...
Positive and negative colossal magnetoresistance in a spin glass selenide spinel (2004)
Parker, D R, Green, M A, Bramwell, S T, Wills, A S, Gardner, J S, Neumann, D A
Er2Ti2O7: Evidence of quantum order by disorder in a frustrated antiferromagnet (2003)
Champion, J D M, Harris, M J, Holdsworth, P C W, Wills, A S, Balakrishnan, G, Bramwell, S T, ...
Wills, A. S., Ballou, R., Lacroix, C.
A new model of localized highly frustrated ferromagnetism is presented: kagome spin ice. By use of analytical and Monte Carlo calculations its massive groundstate entropy is evaluated. Monte Carlo...
Er2Ti2O7: Evidence of Order by Disorder in a Frustrated Antiferromagnet (2001)
Champion, J. D. M., Harris, M. J., Holdsworth, P. C. W., Wills, A. S., Balakrishnan, G., Bramwell, S. T., ...
Er_2Ti_2O_7 has been suggested to be a realization of the frustrated < 111 > XY pyrochlore lattice antiferromagnet, for which theory predicts fluctuation-induced symmetry breaking in a highly...
Conventional and unconventional orderings in the jarosites (2001)
The jarosites make up the most studied family of {\it kagom\'e} antiferromagnets. The flexibility of the structure to substitution of the A and B ions allows a wide range of compositions to be...
Group Theory techniques can aid greatly the determination of magnetic structures. The integration of their calculations into new and existing refinement programs is an ongoing development that will...
Aging and memory properties of topologically frustrated magnets (2001)
Dupuis, V., Vincent, E., Hammann, J., Greedan, J. E., Wills, A. S.
The model 2d kagome system (H3O)Fe3(SO4)2(OH)6 and the 3d pyrochlore Y2Mo2O7 are two well characterized examples of low-disordered frustrated antiferromagnets which rather then condensing into spin...
Order in the Heisenberg Pyrochlore: The Magnetic Structure of Gd2Ti2O7 (2001)
Champion, J. D. M., Wills, A. S., Fennell, T., Bramwell, S. T., Gardner, J. S., Green, M. A.
The rare earth pyrochlore material Gd2Ti2O7 is considered to be an ideal model frustrated Heisenberg antiferromagnet with additional dipolar interactions. For this system there are several untested...
Long-range ordering and representational analysis of the jarosites (2001)
The jarosites are the most studied family of kagomé antiferromagnets. Despite these works little is still known about the detailed causes of the observed magnetic structures. In this article...
Fak, B., Van Dijk, N. H., Wills, A. S.
Moreno and Sauls [Phys. Rev. B 63, 024419 (2000)] have recently tried to reanalyze earlier neutron scattering studies of the antiferromagnetic order in UPt3 with a magnetic field applied in the basal...
Magnetic ordering in diluted Kagome antiferromagnets (2001)
Frunzke, J, Hansen, T, Harrison, A, Lord, J S, Oakley, G S, Visser, D, ...
Order in the Heisenberg pyrochlore: The magnetic structure of Gd2Ti2O7 (2001)
Champion, J D M, Wills, A S, Fennell, T, Bramwell, S T, Gardner, J S, Green, M A
Aging and memory properties of topologically frustrated magnets (2001)
Dupuis, V., Vincent, E., Hammann, J., Greedan, J. E., Wills, A. S.
The model 2d kagome system (H3O)Fe3(SO4)2(OH)6 and the 3d pyrochlore Y2Mo2O7 are two well characterized examples of low-disordered frustrated antiferromagnets which rather then condensing into spin...
Conventional and unconventional orderings in the jarosites (2001)
The jarosites make up the most studied family of {\\it kagom\\\'e} antiferromagnets. The flexibility of the structure to substitution of the A and B ions allows a wide range of compositions to be...
Group Theory techniques can aid greatly the determination of magnetic structures. The integration of their calculations into new and existing refinement programs is an ongoing development that will...
Aging and memory properties of topologically frustrated magnets (2001)
Dupuis, V., Vincent, E., Hammann, J., Greedan, J. E., Wills, A. S.
The model 2d kagome system (H3O)Fe3(SO4)2(OH)6 and the 3d pyrochlore Y2Mo2O7 are two well characterized examples of low-disordered frustrated antiferromagnets which rather then condensing into spin...
Conventional and unconventional orderings in the jarosites (2001)
The jarosites make up the most studied family of {\\it kagom\\\'e} antiferromagnets. The flexibility of the structure to substitution of the A and B ions allows a wide range of compositions to be...
Group Theory techniques can aid greatly the determination of magnetic structures. The integration of their calculations into new and existing refinement programs is an ongoing development that will...
Aging in a topological spin glass (2000)
Wills, A. S., Dupuis, V., Vincent, E., Hammann, J., Calemczuk, R.
We have examined the nonconventional spin glass phase of the 2-dimensional kagome antiferromagnet (H_3 O) Fe_3 (SO_4)_2 (OH)_6 by means of ac and dc magnetic measurements. The frequency dependence of...
Aging in a topological spin glass (2000)
Wills, A.S., Dupuis, V., Vincent, E., Hammann, J., Calemczuk, R.
Using a combination of static and time dependent magnetic susceptibility measurements we have examined the nonconventional spin glass phase of the 2-dimensional kagomé antiferromagnet...
Aging in a topological spin glass (2000)
Wills, A.S., Dupuis, V., Vincent, E., Hammann, J., Calemczuk, R.
Using a combination of static and time dependent magnetic susceptibility measurements we have examined the nonconventional spin glass phase of the 2-dimensional kagomé antiferromagnet...
muSR studies of the Kagome antiferromagnet (H3O)Fe3(OH)6(SO4)2 (2000)
Harrison, A, Kojima, K M, Wills, A S, Fudamato, Y, Larkin, M I, Luke, G M, ...
Aging in a topological spin glass (2000)
Wills, A. S., Dupuis, V., Vincent, E., Hammann, J., Calemczuk, R.
We have examined the nonconventional spin glass phase of the 2-dimensional kagome antiferromagnet (H_3 O) Fe_3 (SO_4)_2 (OH)_6 by means of ac and dc magnetic measurements. The frequency dependence of...
Aging in a topological spin glass (2000)
Wills, A. S., Dupuis, V., Vincent, E., Hammann, J., Calemczuk, R.
We have examined the nonconventional spin glass phase of the 2-dimensional kagome antiferromagnet (H_3 O) Fe_3 (SO_4)_2 (OH)_6 by means of ac and dc magnetic measurements. The frequency dependence of...
Magnetic correlations in deuteronium jarosite, a model S=5/2 Kagome antiferromagnet (1996)
Wills, A. S., Harrison, A, Mentink, S. A. M., Mason, T. E., Tun, Z.
Deuteronium jarosite, (D_3O)Fe_3(SO_4)_2(OD)_6, contains a kagome lattice of Heisenberg spins, S=5/2, with a coverage of 97+-1%. DC and AC susceptibility measurements show strong in-plane...