add permittivity, compressive strength and annotation for mechanical properties and seven new materials

src/data/SiO2.json

@@ -0,0 +1,28 @@
+{
+  "Name": "Fused quartz",
+  "Name_de": "Quarzglas",
+  "Formula": "SiO2",
+  "Electromagnetic Data": {
+    "epsilon_r": ["7±1", "F/m"]
+  },
+  "Mechanical Properties": {
+    "T": ["20-25", "°C"],
+    "rho": [2203, "kg/m³"],
+    "E": [71.4, "GPa"],
+    "G": [31.26, "GPa"],
+    "K": [37, "GPa"],
+    "nu": 0.17,
+    "R_m": [48.3, "MPa"],
+    "R_m'": [">1100", "MPa"],
+    "Hardness": {
+      "HM": "5.9±0.6"
+    }
+  },
+  "Thermodynamic Properties": {
+    "Crystal": {
+      "alpha": [0.55, "µm/m/K"],
+      "lambda": [1.3, "W/m/K"],
+      "cp": [830, "J/kg/K"]
+    }
+  }
+}