Magnetocaloric and structural properties of SmMn2Ge2

Pressure-induced changes in the magnetic and magnetocaloric properties ofRMn2Ge2(RKumar1, Суреш2, Nigam3 et al. 2008Phys. Rev. B462260View full textAdd to dashboardCite

“…As is clear from the inset, at ambient pressure, close to T 1 , the entropy change is positive ͑negative MCE͒ with a magnitude, i.e., ͑⌬S M ͒ max , of about 0.6 J/kg K, whereas it is negative ͑positive MCE͒ close to T 2 . Such a change in the sign of MCE has been reported by Koyama et al 12 and Han et al 13 as well. It was also observed that the entropy change ͑at ambient pressure͒ decreases with increase in field.…”

“…The Rietveld refinement of room-temperature powder x-ray diffractograms confirms that both 12 have reported that there is an abrupt change in the unit-cell volume as the materials enter the AFM phase on cooling. These authors have also shown that in presence of a field, there is no abrupt change in the lattice parameters near T 1 as well as T 2 .…”

“…Among the various compounds of this series, SmMn 2 Ge 2 has attracted special attention owing to the anomalous magnetic and related properties. [10][11][12][13] As a probe to understand the magnetovolume effect, we have studied the effect of hydrostatic pressure on the magnetic properties of SmMn 2 Ge 2 . The same studies have also been carried out on GdMn 2 Ge 2 which is isostructural to SmMn 2 Ge 2 , but which shows quite different magnetic properties.…”

Magnetic Properties and Magnetocaloric Effect οf R1-xR'xMn2Ge2Compounds

“…This value is similar to the data |∆S m (T 1 )| = 1.4 J K −1 kg −1 [12] and |∆S m (T 1 )| = 1.6 J K −1 kg −1 [13]. The sign of |∆S m (T 1 )| is negative, suggesting that an applied magnetic field reduced the magnetic entropy in the AF1 phase.…”

“…At the magnetic phase transition temperature T 2 , the value of |∆S m (T 2 )| = 2.0 J K −1 kg −1 is positive and greater than 1.3 J K −1 kg −1 in Ref. [12]. The entropy change estimated for Sm 0 .…”