Cvitanić, Tonči
Šurija, Vinko
Prša, Krunoslav
Zaharko, Oksana
Kupčić, Ivan
Babkevich, Peter
Frontzek, Matthias
Požek, Miroslav
Berger, Helmuth
Magrez, Arnaud
Rønnow, Henrik M.
Grbić, Mihael S.
Živković, Ivica
Singlet state formation and its impact on the magnetic structure in the tetramer system SeCuO3
Physical Review B
10.1103/PhysRevB.98.054409
98
5
054409
We present an experimental investigation of the magnetic structure in a tetramer system SeCuO3 using neutron powder-diffraction and nuclear resonance techniques. We establish a commensurate antiferromagnetic ordering with a propagation vector k = (0, 0, 1). The order parameter follows a critical behavior near T-N = 8 K with a critical exponent beta = 0.32 in agreement with a three-dimensional universality class. Evidence is presented that a singlet state starts to form on tetramers at temperatures as high as 200 K, and its signature is preserved within the ordered state through a strong renormalization of the ordered magnetic moment on two nonequivalent copper sites m(Cu1) approximate to 0.35(mu B) and m(Cu2) < 0.8(mu B) at 1.5 K.
2018