## 3 Results
### X-ray Powder Diffraction (XRD)  
The XRD patterns of the nanoparticles synthesized using cork oak extract showed distinct peaks corresponding to aluminum phosphate. The prominent peaks at specific 2 theta values matched the reference patterns for aluminum phosphate (AlPO4), confirming its presence (Figure 4).  
Intense diffraction peaks were observed at the following 2\(\theta\) values: 27.32\({}^{\circ}\); 29.74\({}^{\circ}\); 32.74\({}^{\circ}\); 39.31\({}^{\circ}\); and 44.69\({}^{\circ}\). These peaks indicate the presence of aluminum phosphate, corresponding to the reference 04-018-2837 from the ICDD database. Other peaks at 20 values were 23.51\({}^{\circ}\), 41.54\({}^{\circ}\), and 43.65\({}^{\circ}\), which corresponded to the reference 05-001-0464 from the ICDD database. Thus, the XRD analysis revealed that the synthesized aluminum phosphate nanoplates exhibited two distinct crystal systems. The primary crystal system identified is triclinic (anorthic), as matched with the reference pattern 04-018-2837 from the ICDD database. This system is characterized by its low symmetry, where all three axes have different lengths, and none of the angles are 90\({}^{\circ}\). Such irregularity in the crystal structure is uncommon and highlights the unique formation of nanoplates via this green synthesis method. This system's structural complexity can lead to unique and direction-dependent properties in materials. Three axes (a, b, and c) are all of different lengths. None of the angles (\(\alpha\), \(\beta\), \(\gamma\)) between the axes are 90 degrees; each angle is different. As a result, the unit cell the smallest repeating unit in the crystal has a very irregular shape. The lattice parameters of the phase are a = 6.13280 (10) A, b = 7.51510 (10) A, c = 8.58010 (10) A, \(\alpha\) = 98.2630 (7)\({}^{\circ}\), \(\beta\) = 104.6220 (8)\({}^{\circ}\), \(\gamma\) = 102.1398 (8)\({}^{\circ}\).  
In addition, we also observed a secondary phase that corresponded to a monoclinic crystal system, matched with reference pattern 05-001-0464. This system is defined by two axes forming 90\({}^{\circ}\) angles, while the third angle deviates, giving it a different symmetry. The presence of both triclinic and monoclinic phases suggests complex crystallization dynamics, likely influenced by the composition of the cork oak somatic embryo extract.  
Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray Spectroscopy (EDX)  
The transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analysis provided detailed insights into the morphology and size of the aluminum nanopar  
Figure 4: XRD profile of AlNPs obtained by reaction of _Q. suber_ somatic embryos extract with Al(NO3)3.9H2O; in the insert, the table with the identifications. Peaks identifying the presence of aluminum phosphate have been listed.  
ticles (ANNPs) synthesized. Noteworthy, the nanoparticles synthesized using cork oak somatic embryo extract exhibited a nanoplate morphology. These nanoplates were extremely thin (Figure 5A,B), transparent, and had a wide range of lateral dimensions. All types of nanoparticles were well-dispersed with minimal aggregation, indicating effective stabilization by the phytochemicals present in the plant extract.  
High-resolution TEM and SEM images showed that the nanoplates had distinct edges and faces, characteristic of their crystalline nature.  
The elemental composition of the nanoplates has been deduced using EDX in conjunction with SEM and TEM. The EDX analysis of the cork oak-derived nanoplates confirmed the presence of aluminum (Figure 5C,D), indicating a successful synthesis of phosphate aluminum nanoplates.