A magnetic field driven quantum critical point (QCP) is studied experimentally in the Ce₃Al magnetically anisotropic intermetallic compound, which shows both antiferromagnetic (AFM) ordering and heavy–fermion behavior. Measurements of the magnetic susceptibility, the magnetoresistance and the specific heat on a Ce₃Al monocrystalline sample performed down to 0.35 K in magnetic fields up to 9 T demonstrate that the QCP is anisotropic regarding the orientation of the magnetic field relative to the magnetically easy direction. External magnetic field drives the AFM transition continuously toward zero temperature when applied in the (a, b) easy plane, reaching the QCP at the critical field 4.60.4 T, where a quantum phase transition from the AFM to the paramagnetic state takes place. The magnetoresistance experiments below 1 K indicate that intermediate magnetic states may have formed near the QCP. For the field applied along the c hard direction, the QCP has not been observed within our experimental range of the magnetic field. The anisotropic, magnetic field driven QCP in the Ce₃Al results from competition of the exchange interaction with the Zeeman interaction in the presence of a large magnetocrystalline anisotropy. The anisotropy of the QCP is a consequence of the fact that the magnetic anisotropy locks the magnetization into the easy plane and cannot be pulled out of the plane by the available laboratory field. Consequently, only the component of the magnetic field vector that lies in the easy plane participates in the QCP formation. In AFM systems with a large magnetic anisotropy, the magnetic field driven QCP is a continuous variable of the magnetic field vector orientation relative to the easy direction.

在Ce ₃ Al磁性各向异性金属间化合物中，对磁场驱动的量子临界点（QCP）进行了实验研究，它既显示了反铁磁（AFM）的有序性，又显示了重铁磁行为。对在最高9 T的磁场中低至0.35 K的Ce ₃ Al单晶样品上的磁化率，磁阻和比热的测量表明，QCP在磁场相对于易磁化方向的取向方面是各向异性的。当施加在（a，b）易平面中时，外部磁场驱使AFM连续向零温度过渡，并在临界场达到QCP4.60.4 T，其中发生了从AFM到顺磁态的量子相变。低于1 K的磁阻实验表明，可能在QCP附近形成了中间磁态。沿着所施加的场Ç硬方向上，QCP尚未我们的实验范围的磁场内观察到。Ce ₃中由各向异性磁场驱动的QCPAl是由于在大的磁晶各向异性的情况下交换相互作用与塞曼相互作用的竞争而产生的。QCP的各向异性是以下事实的结果：磁各向异性将磁化作用锁定在容易的平面中，并且无法通过可用的实验室磁场从平面中拉出。因此，仅在易平面中的磁场矢量分量才参与QCP的形成。在具有较大磁各向异性的AFM系统中，磁场驱动的QCP是磁场矢量方向相对于易方向的连续变量。