Volume 80, Number 2, October 2007
Article Number 27001
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 13 September 2007
EPL, 80 (2007) 27001
DOI: 10.1209/0295-5075/80/27001

Tunable magnetocaloric effect in RTi $_{1-{\rm
x}}$Mo$_{\rm x}$Ge (R= Tb, Er) (x=0, 0.15) compounds

R. Nirmala1 and S. K. Malik2

1  Tata Institute of Fundamental Research - Mumbai 400-005, India
2  International Centre for Condensed Matter Physics - ICCMP, University of Brasilia - Brasilia, Brazil

received 9 July 2007; accepted in final form 22 August 2007; published October 2007
published online 13 September 2007

The tetragonal layered compounds TbTiGe and ErTiGe order antiferromagnetically at 276 K and 39 K, respectively. Partial substitution of Mo for Ti in these two compounds modifies the magnetic interactions giving rise to a ferromagnetic ground state which results in an enhanced magnetocaloric effect. The magnetic entropy change in ${\rm ErTi}_{0.85}{\rm Mo}_{0.15}{\rm Ge}$ for a magnetic field change of 5 T is $\sim 10.5\,{\rm J/kg/K}$ as against $\sim 0.8\,{\rm J/kg/K}$ for ErTiGe in the vicinity of the magnetic transition. Thus, magnetocaloric properties of such layered materials may be tunable by suitable chemical substitutions.

75.30.Sg - Magnetocaloric effect, magnetic cooling.
75.50.Cc - Other ferromagnetic metals and alloys.
75.47.-m - Magnetotransport phenomena; materials for magnetotransport.

© Europhysics Letters Association 2007