La_1.3−xY_xSr_1.7Mn₂O₇ (x = 0, 0.025) samples are prepared by the conventional solid-state reaction. X-ray diffraction spectrum reveals that the samples are in the Sr₃Ti₂O₇-type tetragonal phase with the space group I4/mmm. By decreasing the temperature, two samples exhibit the paramagnetic phase at high temperatures to two-dimensional short-range-ordered ferromagnetic states at the intermediate temperatures and finally three-dimensional long-range-ordered ferromagnetic states. Furthermore, the doped sample also demonstrates antiferromagnetic ordering in the low-temperature region. The Arrott curve and calibration curve indicate that the sample behaves as a first-order phase transition. When the applied magnetic field is 6 T, the maximum magnetic entropy change (\(\Delta S_{M}\)) occurs in the two samples in the vicinity of the three-dimensional ordered temperature (T^3D_c), and the value of \(\Delta S_{M}\) for the two samples reaches—4.81 J/kg K and—3.82 J/kg K, respectively. In addition, the relative cooling power is 108 J/kg and 112.2 J/kg at \(\mu_{0} H = 3\;T\), respectively. Although the doping of Y reduces T^3D_c, \(\Delta S_{M}\) and the first-order phase transition character, the relative cooling power is enhanced, thus indicating its potential to realize magnetic refrigeration in high-temperature regions (T > 77 K).

中文翻译：

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钇掺杂对双层钙钛矿La 1.3 Sr 1.7 Mn 2 O 7的磁性和磁熵变的影响

通过传统的固态反应制备La _{1.3− x} Y _x Sr _1.7 Mn ₂ O ₇（x  = 0，0.025）样品。X射线衍射光谱表明样品位于Sr ₃ Ti ₂ O _7中型四方相，空间群为I4 / mm。通过降低温度，两个样品在高温下表现出顺磁性相，在中间温度下呈现二维短程铁磁态，最后呈现三维长程铁磁态。此外，掺杂样品在低温区域也表现出反铁磁有序性。Arrott曲线和校准曲线表明样品表现为一阶相变。当施加的磁场为6 T时，在三维有序温度（T ^3D _c）附近的两个样本中发生最大磁熵变（\（\ Delta S_ {M} \）），并且的\（\德尔塔S_ {M} \）对于这两个样品，分别达到-4.81 J / kg K和-3.82 J / kgK。另外，在\（\ mu_ {0} H = 3 \; T \）时，相对冷却功率分别为108 J / kg和112.2 J / kg 。尽管Y的掺杂降低了T ^3D _c，\（\ Delta S_ {M} \）和一阶相变特性，但相对冷却功率得到了增强，从而表明了其在高温区域实现磁制冷的潜力（T  > 77 K）。