Device oriented magnetoelastic properties of TbxDy1−xFe1.95 (x=0.27, 0.3) at elevated temperatures

In order to assess the potential of the highly magnetostrictive compound Terfenol‐D (composition TbxDy1−xFe1.95, where x=0.3 or 0.27) for device applications in the temperature range 20–300 °C, measurement of magnetostrictive strain (λ), differential strain coefficient (d33), and magnetomechanical coupling coefficient (k33) have been made against applied dc field (≤120 kA/m), uniaxial pressure (≤20 MPa), and temperature. Comparing the two compositions at elevated temperatures has shown that large grain oriented material of the composition Tb0.3Dy0.7Fe1.95 has higher strains and d coefficients at elevated temperatures than small grain oriented material of composition Tb0.27Dy0.73Fe1.95, but for optimum coupling efficiency Tb0.27Dy0.73Fe1.95 is preferable.