%0 Journal Article
%A Chang, L. J.
%A Schweika, W.
%A Kao, Y.-J.
%A Chou, Y. Z.
%A Perßon, J.
%A Brückel, T.
%A Yang, H. C.
%A Chen, Y. Y.
%A Gardner, J. S.
%T Magnetic correlations in HoxTb2-xTi2O7
%J Physical review / B
%V 83
%N 14
%@ 1098-0121
%C College Park, Md.
%I APS
%M PreJuSER-15570
%P 144413
%D 2011
%Z This work was supported in Taiwan by Grants No. NSC 96-2739-M-213-001, No. NSC 99-2112-M-007-020 (LJC), No. NSC 97-2628-M-002-011-MY3, and No. NTU 98R0066-65, -68 (Y.Z.C. and Y.J.K.).
%X Polycrystalline samples of HoxTb2-xTi2O7 (0 < x < 2) have been prepared and characterized for their structural and magnetic properties. The parent compounds of this solid solution are the spin ice Ho2Ti2O7 and the spin liquid Tb2Ti2O7. Specific-heat measurements on HoTbTi2O7 (x = 1.0) reveal the absence of a long-range order state above 0.5 K. The integrated entropies of all HoxTb2-xTi2O7 specimens up to 30 K scale well with the ratio of spin ice and spin liquid in the composition. The neutron diffraction spectrum of HoTbTi2O7 exhibits a dipolar spin-ice pattern and can be well described by mean-field theory for < 111 > Ising spins, nearest-neighbor exchange, and dipolar interactions. Inelastic neutron scattering on HoTbTi2O7 reveals two dispersionless excitations, one of similar to 2.5 meV out of the ground state, and a 4-meV transition out of an excited state. We argue that these data suggest that the very strong single-ion effects of Ho2Ti2O7 and Tb2Ti2O7 persist in the HoxTb2-xTi2O7(0 < x < 2) solid solution, whereas the Tb-Ho correlations are weak, resulting in small shifts in the energy scales but with no dramatic effect on the bulk properties.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000291973500004
%R 10.1103/PhysRevB.83.144413
%U https://juser.fz-juelich.de/record/15570