Year: 2010
Type: article
Abstract: The critical properties of the ferromagnet CdCr 2 Se 4 around the paramagnetic-ferromagnetic phase transition have been investigated. It is found that the 3D-Heisenberg model is the best one to describe the critical phenomena around the critical point. Critical exponents β=0.337±0.03 and γ=1.296±0.109 at T C =130.48±0.34 are obtained. In addition, the critical exponent δ=4.761±0.129 is determined separately from the isothermal magnetization at T C . These critical exponents fulfill the Widom scaling relation δ=1+γ/β. Based on these critical exponents, the magnetization-field-temperature ( M - H - T ) data around T C collapses into two curves obeying the single scaling equation M ( H , ε)=ε β f ± ( H /ε β+γ ). Although the 3D-Heisenberg model is the most satisfactory model to describe this system, critical exponents for CdCr 2 Se 4 are slightly smaller than the theoretical exponents (β=0.36, γ=1.39 and δ=4.8). This indicates that the exchange interaction J ( r ) decays slower than r − 5 in this system, which can be attributed to the spin-lattice coupling.
Source: Europhysics Letters (EPL)
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2000743716