Field-induced Bose-Einstein condensation of triplons up to 8 K in Sr3Cr2O8.
Single crystals of the spin dimer system Sr(3)Cr(2)O(8) have been grown for the first time. Magnetization, heat capacity, and magnetocaloric effect data up to 65 T reveal magnetic order between applied fields of H(c1) approximately 30.4 T and H(c2) approximately 62 T. This field-induced order persists up to T(c)(max) approximately 8 K at H approximately 44 T, the highest observed in any quantum magnet where H(c2) is experimentally accessible. We fit the temperature-field phase diagram boundary close to H(c1) using the expression T(c) = A(H-H(c1))(nu). The exponent nu = 0.65(2), obtained at temperatures much smaller than T(c)(max), is that of the 3D Bose-Einstein condensate (BEC) universality class. This finding strongly suggests that Sr(3)Cr(2)O(8) is a new realization of a triplon BEC where the universal regimes corresponding to both H(c1) and H(c2) are accessible at (4)He temperatures.
Aczel
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AA
Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada, L8S 4M1.
Kohama
Y
Y
Marcenat
C
C
Weickert
F
F
Jaime
M
M
Ayala-Valenzuela
O E
OE
McDonald
R D
RD
Selesnic
S D
SD
Dabkowska
H A
HA
Luke
G M
GM