Bulk samples of La(Fe,Co,Si) ₁₃ have been prepared by powder metallurgy starting from elemental powders and cast master alloys. After sintering at about 1400 K for a few hours, the samples achieve densities of about 7.2 g/cm ³ . For ternary La(Fe _0.893 Si _0.107 ) ₁₃ the magnetic entropy change for a field variation of 16 kOe and the adiabatic temperature change for a field variation of 17 kOe amounts to 21.9 J/kgK and 4.2 K at a temperature of 193 K, respectively. For this composition, the thermal and the field hysteresis were determined to be 2.5 K and 2.2 kOe, respectively. With increasing Si content the hysteresis as well as the entropy change decreases. By increasing the Co content from La(Fe _0.865 Co _0.05 Si _0.085 ) ₁₃ to La(Fe _0.803 Co _0.112 Si _0.085 ) ₁₃ the peak temperature of the magnetic entropy change was tailored to the commercial relevant range of 254 K-336 K. The Co-containing samples hardly showed any hysteresis at all. Such powders were pressed in a die and sintered to fully dense blocks of about 23times19times12 mm . The blocks can be machined by conventional techniques to the shapes required in magnetic refrigeration prototypes.

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