Chapter 170 Static and dynamic stresses

CoF2: a model system for magnetoelastic coupling and elastic softening mechanisms associated with paramagnetic ↔ antiferromagnetic phase transitions

“…There is no equivalent tail in e 3 , implying that the coupling coefficient for an equivalent term λσ m e 2 3 is small and, presumably, that the softening of C 33 would also be small. According to this treatment, the tail in e 2 1 and the variation of | f 2 / f 2 o | are measures of the dynamical average of the degree of short range order as T → T N . It should also be pointed out that additional contributions to the shear modulus may come from C 44 , C 66 , etc, through terms such as λσ 2 m e 2 4 and λσ 2 m e 2 6 , but in MnF 2 at least, the precursor softening of C 44 and C 66 is very small [59].…”

“…Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. materials including metals, intermetallics, oxides, sulphides and halides [1][2][3]. In descriptions of structural phase transitions, the distortions would be referred to as spontaneous strain, but in magnetism the effects are usually described in terms of magnetostriction, exchange striction or magnetoelastic coupling.…”

Influences of La and Ce doping on giant magnetocaloric effect of EuTiO

“…The basic mechanism of the MCE is magneto-thermodynamic phenomenon of a magnetic material, which is evaluated from the isothermal magnetic entropy change (−∆S M ) and the adiabatic temperature change (∆T ) in a changing magnetic field. [1] The researches of magnetic refrigeration materials mainly concentrate in the areas of room temperature and low temperature, such as LaCaMnO 3 , [2] Gd 5 Si 2 Ge 2 , [3] MnFeX (X = P, As, Si, Ge), [4] and Ni-Mn-Ga, [5,6] RCo 2 , [7,8] RNi 2 (R = Gd, Dy, Ho, Er), [9][10][11] RCoAl (R = Tb, Dy, Ho), [12,13] etc.…”

Amorphization Induced High Magneto-Caloric Effect of Gd 55 Al 20 Ni 25 Ternary Alloy

“…On the other hand, it is regarded that the materials with sharp −∆S m peak is unsuitable for applications in magnetic refrigeration technology even though they exhibit high peak entropy change (−∆S peak m ). [1,20] Therefore, the MCE temperature range ∆T MCE , which could be obtained by the temperature width at the half maximum of −∆S peak m , is another important parameter concerning the refrigerant efficiency of the materials. [3,21,22] It should be noted that crystalline materials with large −∆S peak m , such as Gd 5 Si 2 Ge 2 and Ni 2 Mn 1−x Cu x Ga, usually exhibit ∆T MCE lower than 30 K. [4,23] However, in the amorphous samples with slightly lower −∆S peak m , for example, in Gd 55 Al 20 Ni 25 BMG, ∆T MCE reaches to over 70 K. The refrigerant capacity (RC), which is defined as…”